Abstract

Background:Choroid plexus tumors (CPT) in the pediatric population are usually discovered in symptomatic patients often with symptoms of increased intracranial pressure, with hydrocephalus as the most common presentation, along with seizures, subarachnoid hemorrhage, or focal neurological deficit. Most CPTs are found to be benign choroid plexus papillomas (CPP), whereas a small number are intermediate and malignant choroid plexus carcinomas (CPC). Total surgical resection is the established definitive treatment for symptomatic CPP.

Case Description:We describe a young female who was found to have an incidental CPT during workup for recent head trauma without neurological deficits or hydrocephalus. She underwent a surgical operation to remove the tumor successful, with 1-year follow-up showing no recurrence and normal developmental milestones.

Conclusion:This rare presentation of an asymptomatic CPT brings attention to the fact that there is no clear evidence for how or when to treat such patients. Because discovery of a CPT in an asymptomatic patient is uncommon, the treatment plan appears to be developed on a case-by-case basis. We hope to generate discussion for establishing an agreed upon treatment approach for CPTs in asymptomatic patients.

Keywords: Child nervous system, choroid plexus papilloma, choroid plexus tumor, incidental, oncology

INTRODUCTION

Choroid plexus tumors (CPT) in the pediatric population are usually discovered, unfortunately, when patients present symptomatically. Symptoms of increased intracranial pressure (ICP) with hydrocephalus are the most common presentation, along with seizures, subarachnoid hemorrhage (SAH), or focal neurological deficit.[ 1 ] Most are found to be benign World Health Organization (WHO) grade I choroid plexus papillomas (CPP), whereas a small number are intermediate and malignant choroid plexus carcinomas (CPC). Total surgical resection is the definitive treatment for symptomatic CPTs.[ 1 ] We describe a patient who was found to have an incidental CPT following a fall. She was asymptomatic with respect to the mass and had been developing normally without radiological evidence of hydrocephalus. We discuss the decision whether to operate or not.

CASE REPORT

An 11-month-old girl presented to the emergency room bleeding from her ear 2 days after an accidental fall rolling off the bed and striking her head. The patient was otherwise healthy with no relevant medical, birth, or social history. An initial computed tomography (CT) of the head was negative for hemorrhage [ Figure 1 ]; however, a small hyperdensity was noted in the right temporal horn. A subsequent magnetic resonance imaging (MRI) [ Figure 2 ] identified a well-circumscribed mass 1 cm in diameter without hemorrhage or hydrocephalus. The patient was discussed at a multidisciplinary tumor board and, after some controversy, the decision was made to proceed with surgical resection [ Figure 3 ]. The lesion was successfully removed and the patient made a full recovery without any neurological deficit. Pathology revealed the lesion to be a CPP WHO grade I.

Figure 1

Computed tomography of the head revealing a hyperdense focus measuring up to 6.5 mm in the right temporal lobe

Figure 2

Magnetic resonance imaging of the head with and without contrast revealing a right lateral ventricular 8mm lesion likely associated with the choroid plexus

Figure 3

Tumor forceps removing the choroid plexus papilloma from the right lateral ventricle

DISCUSSION

CPTs are rare, according to the Canadian Pediatric Brain Tumor Consortium experience, the annual age-adjusted incidence rate was 0.22+0.12 (95% CI 0.16–0.28)/100,000 in children less than 3 years of age.[ 3 ] The treatment of choice for CPTs is surgery with total resection being the goal. Complete removal of the tumor is generally curative and leads to resolution of the presenting symptoms in nearly all patients. Even in CPC, total resection (if feasible) leads to the best possible outcome. After incomplete surgery, a “wait-and-see” policy seems to be justified for all CPT. The separation of CPT based on MIB-1 labeling, p53 status, and histology into CPP, atypical papilloma, and carcinoma can direct follow-up and adjuvant treatment plans.[ 2 ] For example, adjuvant multi-agent chemotherapy and craniospinal radiotherapy following surgery should be considered for CPC's.[ 8 9 ]

In the case of an incidentally found CPT, there is no evidence indicating whether prompt surgical removal is best, or that surgery should be withheld until routine surveillance shows either radiographic changes in the tumor, an increase in cerebrospinal fluid (CSF) volume (hydrocephalus), or the patient becomes symptomatic.

The benefit to waiting until hydrocephalus develops is that it lessens the length of the corridor to the ventricles and increases the space around the tumor giving greater access to its blood supply. This may allow for an easier resection of the CPT. The drawback to this is that hydrocephalus may not be the presenting symptom, and that the first neurological insult from mass effect, a SAH, or seizures may result in focal deficits that do not resolve after removal of the tumor. Furthermore, there is some evidence that cognitive deficits and regression may develop as these tumors grow.[ 6 ] The drawbacks to a watchful waiting approach are many. First, in a child this age, general anesthesia is required to acquire serial MR scans. This is burdensome and not devoid of risks. To pursue CT imaging alleviates the need for MR scans, but then requires radiation and a contrast dye load, which again carry risks. And of course, one would not wait for the symptoms to present itself to repeat imaging and then make a surgical decision.

Matsuyama et al. reported a case of an incidentally found CPP in a 19-year-old patient. The CPP extended from the third ventricle into the right lateral ventricle. The tumor was operated on promptly. They reported that the slightly enlarged right lateral ventricle contributed to the decision as this made the tumor more accessible.[ 5 ]

There may be a role for preoperative embolization to reduce the amount of intraoperative blood loss, and is therefore, associated with higher rates of total resection and lower operative morbidity and mortality.[ 7 ] Selective embolization of CPTs has yet to be shown to be an effective stand-alone treatment strategy.[ 7 ] As patients usually present symptomatically, embolization is unlikely to be the best treatment option and so surgical resection is generally the best choice. Furthermore, embolization is not without risk, particularly given that the anterior and posterior choroidal arteries that supply choroid plexus tumors also supply eloquent structures and may not be significantly dilated in children with these tumors.[ 7 ]

Radiosurgery may also be a possible treatment for CPTs, however, little is known about the efficacy or use in asymptomatic patients as the risks may outweigh the benefits of use.[ 2 ]

This rare presentation of an asymptomatic CPT brings attention to the fact that there is no clear evidence for how or when to treat such patients. We opted to operate promptly, but electively, to prevent any long-term sequelae from the CPT. A clear treatment plan is established for symptomatic patients but is not as well developed for asymptomatic patients. As discovery of a CPT in an asymptomatic patient is extremely rare, the treatment plan appears to be developed on a case-by-case basis. For the initial workup, even in the asymptomatic patient, it may be that an MRI scan is warranted when a hyperdense lesion near a ventricle is discovered, as was done for our patient. In the event that an MRI is not performed, a follow- up CT scan should be done to monitor for changes or to confirm the resolution of blood if hemorrhage was suspected.

CONCLUSION

After our literature search, we were still unclear on how to proceed given the paucity of data on the natural history of these tumors. We made our decision given that as the tumor grows and will ultimately require surgery, the psychological trauma to the child is minimized by operating in this age group as well as the need for tissue diagnosis. As a small percentage of these may be high grade, it is worth the risk to identify this patient earlier, especially because the extent of resection is significantly associated with increased survival.[ 4 ] On 1-year follow-up, our patient is doing quite well as she is reaching normal growth and developmental milestones. A 1-year MRI [ Figure 4 ] was unremarkable for any residual or abnormal enhancement except postsurgical changes. Overall, surgery was warranted; the decision to wait or operate immediately could be argued both ways, but we felt it was in the best interest for the child to remove this benign tumor shortly after the incidental finding.

Figure 4

Status post lesion resection from the right temporal horn without evidence of abnormal enhancement or recurrent tumor

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Greenberg MS.editorsHandbook of Neurosurgery, ed. New York, NY: Thieme Publishers; 2010. p.

2. Kim IY, Niranjan A, Kondziolka D, Flickinger JC, Lunsford LD. Gamma knife radiosurgery for treatment resistant choroid plexus papillomas. J Neurooncol. 2008. 90: 105-10

3. Lafay-Cousin L, Keene D, Carret AS, Fryer C, Brossard J, Crooks B. Choroid plexus tumors in children less than 36 months: The Canadian Pediatric Brain Tumor Consortium (CPBTC) experience. Childs Nerv Syst. 2011. 27: 259-64

4. Lam S, Lin Y, Cherian J, Qadri U, Harris DA, Melkonian S. Choroid plexus tumors in children: A population-based study. Pediatr Neurosurg. 2013. 49: 331-8

5. Matsuyama T, Masuda A. A rare case of choroid plexus papilloma in the third ventricle. No Shinkei Geka. 1992. 20: 1269-72

6. Nagib MG, O’Fallon MT. Lateral ventricle choroid plexus papilloma in childhood: Management and complications. Surg Neurol. 2000. 54: 366-72

7. Slater LA, Hoffman C, Drake J, Krings T. Pre-operative embolization of a choroid plexus carcinoma: Review of the vascular anatomy. Childs Nerv Syst. 2016. 32: 541-5

8. Strojan P, Popovic M, Surlan K, Jereb B. Choroid plexus tumors: A review of 28-year experience. Neoplasma. 2004. 51: 306-12

9. Wrede B, Liu P, Wolff JE. Chemotherapy improves the survival of patients with choroid plexus carcinoma: A meta-analysis of individual cases with choroid plexus tumors. J Neurooncol. 2007. 85: 345-51

Abstract

Background:Pilocytic astrocytoma (PA) is the most prevalent central nervous system (CNS) tumor in pediatric population and accounts for an approximate of 5–6% of all gliomas. This neoplasm can occur at all levels of the neuraxis, with majority (67%) arising in the cerebellum and optic pathway. PAs are World Health Organization Grade I tumors and are the most benign of all astrocytomas characterized by an excellent prognosis. Other differentials include subependymal giant cell astrocytoma (SEGA), ependymoma, meningioma, and low-grade gliomas such as pilocytic or diffuse astrocytoma; calcification is more commonly regarded as a feature of benign or slow-growing tumors.

Case Description:We present a case of a 17-year-old female presenting with an unusual cause of hydrocephalus, a rare case of a calcified pilocytic astrocytoma as an intraventricular tumor.

Conclusion:PA rarely presents as an intraventricular tumor and should be included in the differential diagnosis of a large mass with massive intratumoral calcification.

Keywords: Intraventricular tumor, pilocytic astrocytoma, slow-growing tumors

INTRODUCTION

The central nervous system (CNS) is the most common site of primary solid tumors in pediatric population. Among pediatric patients (age 0–19 years), pilocytic astrocytoma (PA) is the most prevalent CNS tumor, representing 19.7% of all cases and accounting for an approximate of 5–6% of all gliomas.[ 2 ] This neoplasm can occur at all levels of the neuraxis, with majority (67%) arising in the cerebellum and optic pathway.[ 14 ] PAs are World Health Organization Grade I tumors and are the most benign of all astrocytomas characterized by an excellent prognosis.[ 1 4 ]

Calcification is a subtle and an infrequent finding, seldom seen in the optic nerve or hypothalamic/thalamic tumors or in superficially located cerebral tumors.[ 12 ] Although calcification is more commonly regarded as a feature of benign or slow-growing tumors, the precise mechanism remains unclear. Commonly, calcified brain tumors include oligodendrogliomas, low-grade astrocytomas, craniopharyngiomas, meningiomas, pineal gland tumors, and ependymomas.[ 9 13 ] Intraventricular tumors that can show calcification include ependymomas, choroid plexus tumors, central neurocytomas, and metastatic tumors.[ 17 ]

We present a case of a 17-year-old female presenting with an unusual cause of hydrocephalus, a rare case of a calcified PA as an intraventricular tumor.

CASE REPORT

A 17-year-old old female, with no known comorbidity, presented with complaints of headache off and on for 1 month, which increased over a period of few days, associated with nonbilious, nonprojectile vomiting for 2 weeks. She presented to the emergency department and was referred to the neurosurgery service for further management upon evaluation of symptomatology. On examination, the patient was alert, awake, and oriented in time place and person. She denied any history of seizures, focal deficit, numbness, or any episode of unconsciousness.

General physical examination was unremarkable with normal blood pressure and pulse rate. Motor examination was unremarkable, sensory examination was normal, no cerebellar signs could be elicited, and no gait abnormality was identified. Direct ophthalmoscopy was suggestive of mild papilledema with no evidence of disc cupping or atrophic changes and no blurring of vision. Visual acuity was within normal limits with normal color vision.

On investigation, blood profile was normal. Radiological imaging consisting of magnetic resonance imaging (MRI) of the brain with and without contrast; on T1-weighted postcontrast images, a heterogeneously enhancing mass lesion identified within the lateral ventricles in the proximity of the foramina of Monro [ Figure 1 ]. T2-weighted sequence showed isointense to hyperintense lesion containing abnormal signals, suggestive of calcification and mildly enhancing cysts of variable sizes. There was significant dilatation of the lateral ventricles bilaterally, with an interval increment in size. The rest of the brain parenchyma was normal with gray and white matter differentiation. No acute infarction or intracranial hemorrhage was seen. Major vessels showed normal flow voids and basal cisterns were preserved [ Figure 2 ].

Figure 1

MRI brain post-contrast showing a heterogeneously enhancing space occupying lesion in the lateral ventricles with extension into the foramen of Monro with obstructive hydrocephalus

Figure 2

MRI Brain T1 Weighted coronal images suggestive of a hyperintense lesion occupying the lateral ventricles and extending into the third ventricle. Hydrocephalus also evident

Anesthesia evaluation was done, and after a written and informed consent, the patient underwent neuronavigation-guided (NNG) right-sided frontal craniotomy with excision of space occupying lesion (SOL) and left-sided frontal short tunnel extraventrivular drain (EVD) placement.

A linear incision was made. Intraoperative findings were of a grossly large intraventricular tumor which was moderately vascular containing cystic and necrotic components. The tumor was found to be occupying the septum pellucidum and extending into the lateral ventricles bilaterally. It was obliterating the foramen of Monro and third ventricle and causing biventricular hydrocephalus.

Postoperatively, the patient was uneventfully extubated; however, later in the recovery room patient had two episodes of generalized tonic–clonic seizure which were managed with intravenous antiepileptic medication.

Postoperative CT scan was done which was suggestive of pneumocephalus and postsurgical changes. Bilateral subdural collections were noted. Scan also showed diffuse cerebral edema with hydrocephalus and small intraventricular hemorrhage.

Patient was stepped down while EVD was removed on the fifth postoperative day after a successful challenge. Patient had an uneventful course during the hospital stay and was discharged with an early follow-up.

Histopathology showed multiple fragments of a neoplastic lesion comprising spindle-to-stellate-shaped cells arranged in alternating compact and loose areas [ Figure 3 ]. The background was diffuse fibrillary. Individual tumor cells had elongated cytoplasmic processes and bland looking nuclei. Some areas exhibited multinucleation. There were associated thick walled, hyalinized blood vessels in the stroma along with areas exhibiting Rosenthal fibers and hyaline globules [ Figure 4 ]. Other areas exhibited chicken wire type of capillary network with intervening round-to-oval cells having clear cytoplasm and rounded nuclei. Focal areas showed fragments of native glial tissue with admixed ganglion cells. Immunohistochemically, the tumor cells were diffusely positive for glial fibrillary acidic protein (GFAP) [ Figure 5 ]. Synaptophysin stain was noncontributory. Proliferative index (Ki67 (Mib-1) was low (up to 1–2%). Features were consistent with PA, WHO grade I.

Figure 3

Alternating loose and compact areas characteristic of Pilocytic astrocytoma (×20)

Figure 4

Abundant Rosenthal fibers in Pilocytic astrocytoma (×40)

Figure 5

GFAP shows diffuse staining in pilocytic astrocytoma

On follow-up in the clinic, the patient presented with left-sided hemiparesis with power of 4/5, backache, and generalized lower limb tenderness. Follow-up CT scan showed interval decrease in hydrocephalus with the bifrontal diameter measuring 42 mm which was previously 55 mm in size. There was an interval reduction in the intraventricular hemorrhage; however, a slight interval increase in bilateral subdural collections was noted. Interval resolution of pneumocephalus with interval decrease in cerebral edema was also noted. Patient was followed up with serial MRI brain scans which showed progressive betterment supported by clinical condition.

DISCUSSION

This is a rare presentation of PA as an intraventricular tumor. Intraventricular neoplasms originate from cells forming the ependymal lining or the subependymal plate of the ventricular wall, choroid plexus, and glial lined structures such as septum pellucidum.[ 5 ]

Tumors localized in the lateral ventricles of the cerebral hemispheres account for less than 1% of all intracranial tumors,[ 18 ] but are relatively more frequent in pediatric population. Intraventricular tumors are relatively symptomless until they enlarge and obstruct the pathways of CSF, producing obstructing hydrocephalus and leading to an increased intracranial pressure. Zuccaro and Sosa in a case series of 54 intraventricular tumors in children reported that 38 were benign or low-grade and 16 were anaplastic.[ 21 ] The WHO classification of neuroepithelial tumors of the CNS consists of astrocytic tumors, oligodendroglial tumors, oligoastrocytic tumors, ependymal tumors, choroid plexus tumors, and other neuroepithelial tumors; astrocytic tumors are subclassified as invasive or noninvasive, the noninvasive tumor types including PA is categorized as WHO grade I tumor, of which other differentials include subependymal giant cell astrocytoma (SEGA), ependymoma, meningioma, and low-grade gliomas such as pilocytic or diffuse astrocytoma.[ 11 ] The most frequent tumor types histologically reported were SEGA, choroid plexus papillomas, ependymomas, and astrocytomas.[ 10 ] Most tumors arising within the lateral ventricles were benign or of low-grade malignancy, which is similar to our findings.[ 16 ]

Pilocytic and diffuse astrocytomas were considered as our main differential diagnosis. Kim in his case report elucidated the histology of the viable tumor tissue that showed the presence of Rosenthal fibers and biphasic, compact, spongy pattern of PA, which is in lieu with our findings. Furthermore, degenerative atypia and regressive changes of PA were reported in a study by Tibbetts, similar to our findings;[ 19 ] these changes included markedly hyalinized ectatic blood vessels, intratumoral hemorrhage, and calcification, this was a similar finding to ours. Nuclear pleomorphisms of tumor cells with frequent multinucleation, smudgy chromatin, and intranuclear cytoplasmic inclusions have been frequently reported. Degenerative atypia is considered as characteristic of PA also was significant in our case. Based on these histological findings, a final diagnosis of PA was made. Fisher in his study on prognostic factor for low-grade glioma discussed the significance of the Ki-67 labeling index, which was less than 2%, this was significant to our case. Further, Fisher stated it to be only borderline significant for progression-free survival.[ 14 ] Gliomas that calcify tend to be benign or slow growing;[ 14 20 ] thus, calcification tends to develop over a long period of time,[ 15 ] reflecting tumor chronicity or degenerative changes; therefore, our findings were reciprocative, any form of calcium deposition requires a considerable period of time to develop. Therefore, its presence on radiological evidence, a feature of this case, indicated that the tumor grew rather slowly. The diffuse low-grade astrocytomas are the most common glial neoplasms demonstrating calcifications.[ 3 ] This tumor was a low-grade glioma with intraventricular location. The tumor was histologically diagnosed as PA (WHO grade I).

As illustrated by the WHO, PA is classified as grade I neoplasms and typically have an excellent prognosis. In this regard, tumors amenable to gross total resection (GTR) are considered “cured,” with low risk of tumor recurrence following resection.[ 4 6 7 8 ] However, PAs arising in the optic pathway, brainstem, and diencephalon are not usually amenable to GTR.

A GTR was achieved in our case with subsequent regression of symptoms and interval decrease in intraventricular hemorrhage. Patient was followed with serial MRI brain for recurrence and long term management.

CONCLUSION

PA rarely presents as intraventricular tumor and should be included in the differential diagnosis of a large mass with massive intratumoral calcification.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Budka H. Partially resected and irradiated astrocytoma of childhood: Malignant evolution after 28 years. Acta Neurochir (Wien). 1975. 32: 139-46

2. Last accessed on 2016 Nov 01. Available from: http://www.cbtrus.org/2011-NPCR-SEER/WEB-0407-Report-3-3-2011.pdf.

3. Das DK. Psammoma body: A product of dystrophic calcification or of a biologically active process that aims at limiting the growth and spread of tumor?. Diagn Cytopathol. 2009. 37: 534-41

4. Fernandez C, Figarella-Branger D, Girard N, Bouvier-Labit C, Gouvernet J, Paz Paredes A. Pilocytic astrocytomas in children: Prognostic factors—A retrospective study of 80 cases. Neurosurgery. 2003. 53: 544-55

5. Filippidis AS, Tsonidis CA. Intraventricular brain tumors in children. Pediatr Neurosurg. 1989. 5: 230-3

6. Fisher BJ, Naumova E, Leighton CC, Naumov GN, Kerklviet N, Fortin D. Ki-67: A prognostic factor for low-grade glioma?. Int J Radiat Oncol Biol Phys. 2002. 52: 996-1001

7. Gajjar A, Sanford R, Heideman R, Jenkins JJ, Walter A, Li Y. Low-grade astrocytoma: A decade of experience at St. Jude Children's Research Hospital. J Clin Oncol. 1997. 15: 2792-9

8. Garcia DM, LatiW HR, Simpson JR, Picker S. Astrocytomas of the cerebellum in children. J Neurosurg. 1989. 71: 661-4

9. Geisssinger JD, Bucy PC. Astrocytomas of the cerebellum in children. Arch Neurol. 1971. 24: 125-35

10. Kim YE, Shin HJ, Suh YL. Pilocytic astrocytoma with extensive psammomatous calcification in the lateral ventricle: A case report. Childs Nerv Syst. 2012. 28: 649-52

11. Louis DN, Ohgaki H, Wiestler OD, Cavenee WK, Burger PC, Jouvet A. The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol. 2007. 114: 97-109

12. Makariou E, Patsalides AD. Intracranial calcifications. Appl Radiol. 2009. 38: 48-60

13. Nishio S, Takashita I, Fujii K, Fukui M. Supratentorial astrocytic tumors of the childhood: A clinicopathologic study of 41 cases. Acta Neurochir (Wien). 1989. 101: 3-8

14. Ohgaki H, Kleihues P. Population-based studies on incidence, survival rates, and genetic alterations in astrocytic and oligodendroglial gliomas. J Neuropathol Exp Neurol. 2005. 64: 479-89

15. Okuchi K, Hiramatsu K, Morimoto T, Tsunoda S, Sakaki T, Iwasaki S. Astrocytoma with widespread calcification along axonal fibres. Neuroradiology. 1992. 34: 328-30

16. Piepmeier JM. Tumors and approaches to the lateral ventricles: Introduction and overview. J Neurooncol. 1996. 30: 267-74

17. Scheithauer BW, Hawkins C, Tihan T, VandenBerg SR, Burger PC, Louis DN, Ohgaki H, Wiestler OD, Cavenee WK.editors. Astrocytic tumor. WHO classification of tumours of the central nervous system. Lyon: World Health Organization; 2007. p. 16-

18. Spencer D, Collins W, Sass K, Schmidek H, Sweet W.editors. Surgical management of lateral ventricular tumors. Operative neurosurgical techniques. Philadelphia: Saunders; 1998. p. 583-607

19. Tibbetts KM, Emnett RJ, Gao F, Perry A, Gutmann DH, Leonard JR. Histopathologic predictors of pilocytic astrocytoma event-free survival. Acta Neuropathol. 2009. 117: 657-65

20. Tomita T, Larsen MB. Calcified metastases to the brain in a child: Case report. Neurosurgery. 1983. 13: 435-7

21. Zuccaro G, Sosa F, Cuccia V, Lubieniecky F, Monges J. Lateral ventricle tumors in children: A series of 54 cases. Childs Nerv Syst. 1999. 15: 774-85

Abstract

Background:Pedicle screw instrumentation is widely used for spinal stabilization. However, the accuracy for free-hand screw placement ranges from 69% to 94%. This study assesses the value of the existing classification systems, and investigates their impact on the ability to assess the accuracy of free-hand screw placement.

Methods:Data were collected retrospectively from the medical records of 34 patients who received 224 pedicle screws placed utilizing a free-hand technique. Screw placement was evaluated employing the 2-mm increment and Zdichavsky et al. classification systems. Kappa coefficient and Landis and Koch interpretations were employed for statistical analysis.

Results:The 2-mm increment classification system resulted in a total of 18 (8.03%) misplaced screws. Lateral screw misplacement was observed in 13 (5.8%) instances, with medial pedicle wall penetration being noted in 5 (2.23%). Of the 18 misplaced screws, 4 (22.22%) were classified as minor (≤2 mm), 12 (66.67%) as moderate (2–4 mm), and 2 (11.11%) as severe (>4 mm) (K = 0.882). The Zdichavsky et al. grading system categorized 208 (92.84%) pedicle screws as Ia, 10 (4.46%) as Ib, 1 (0.45%) as IIa, 2 (0.90%) as IIb, 2 (0.90%) as IIIa, and 1 (0.45%) as IIIb grade; this resulted in a total of 16 (7.14%) misplaced screws (K = 0.980). One patient exhibited a new postoperative radiculopathy attributed to poor screw placement. There were no additional early or late postsurgical complications attributed to screw misplacement.

Conclusion:The free-hand pedicle screw placement technique is both safe and effective. Postoperative computed tomography studies; however, are useful to confirm the accuracy of screw placement. Although, the available grading systems proved reliable, easy to use, and clearly reflected the individual surgeon's skills, they do not clearly document whether screws are safely placed.

Keywords: Accuracy, evaluation, grading, pedicle screw

INTRODUCTION

Pedicle screw instrumentation is widely used for the stabilization of the subaxial cervical, thoracic, and lumbar spine.[ 1 ] The accuracy for free-hand screw placement technique varies from 69% to 94%.[ 2 ] Computer-assisted computed tomography (CT) techniques have improved the overall accuracy for pedicle screw placement, and has reduced complication rates. When we compared the two major pedicle screw misplacement evaluation grading systems, the 2-mm incremental system proved to be the most useful.

MATERIALS AND METHODS

In this retrospective observational study, data were collected from the medical records of 34 patients operated on by a single-surgical team utilizing a free-hand technique for the placement of lumbar pedicle screws utilizing a posterior approach with conventional techniques (e.g., anatomical landmarks for guidance). Patients were followed up for a minimum of 12 months. A postoperative CT allowed for direct assessment of the accuracy with which 224 pedicle screws were placed. CT images were independently reviewed by both a neurosurgeon and a radiologist. They employed the two of the most popular grading systems: the 2-mm increment based grading system and the Zdichavsky et al. grading criteria. CT's were evaluated using the RadiAnt DICOM Viewer v. 2.2.9. statistical analysis was performed using the IBM SPSS v. 21. A literature review identified these two and other popular grading systems.

RESULTS

The use of the 2-mm increment classification, resulted in 18 (8.03%) misplaced screws; lateral screw misplacement was observed in 13 (5.8%) instances; medial pedicle wall penetration in 5 (2.23%). Of the 18 misplaced screws, 4 (22.22%) were classified as minor (≤2 mm), 12 (66.67%) as moderate (2–4mm), and 2 (11.11%) as severe (>4 mm) [ Table 1 ]. Interobserver reliability was K = 0.882. Using the Zdichavsky et al. grading system, we categorized the placement of all 224 pedicle screws; 208 (92.84%) pedicle screws were Ia, 10 (4.46%) as Ib, 1 (0.45%) as IIa, 2 (0.90%) as IIb, 2 (0.90%) as IIIa, and 1 (0.45%) as IIIb grade, resulting in a total of 16 (7.14%) misplaced screws [ Table 2 ]. Interobserver reliability was K = 0.980. Only one patient developed a new radiculopathy, requiring early corrective surgery for screw revision. There were no other early or late postsurgery complication.

Table 1

2 mm increment classification system graded patients

Table 2

Zdichavsky et al grading system categorised patients

DISCUSSION

Innovative CT-guided techniques have greatly contributed to minimizing the incidence of pedicle screw misplacement, especially when utilized by experienced surgeons. The superiority of navigation systems is particularly obvious when applied to abnormal/anomalous spinal structures.[ 4 ] However, the cost of the CT-guidance may be prohibitive especially in developing/poor countries where the latter, surgeons must rely solely on their clinical experience and lateral fluoroscopy.

Grading systems

This study compared the value of two systems regarding the free-hand (under fluoroscopy) misplacement of the lumbar pedicle screws. Aosude et al. determined the 2-mm incremental based system was the most accurate to define screw malplacement[ 1 ] [ Table 3 ]. This was compared to a second classification proposed by Zdichavsky et al.[ 5 6 ] [ Figure 1 ].

Table 3

The 2 mm increment classification system

Figure 1

Zdichavsky grading system IA: ≥ 50% of pedicle screw diameter (PSD) within the pedicle & ≥ 50% of PSD within the vertebral body IB: > 50% of PSD lateral outside the pedicle & > 50% of PSD within the vertebral body IIA: ≥ 50% of PSD within the pedicle & > 50% of PSD lateral outside the vertebral body IIB: ≥ 50% of PSD within the pedicle & tip of PS crossing the middle line of the vertebral body IIIA: >50% of PSD lateral outside the pedicle & >50% of PSD lateral outside the vertebral body IIIB: >50% of PSD medial outside the pedicle & tip of PS crossing midline of the vertebral body

We employed the Landis and Koch Kappa interpretation system for statistical assessment[ 3 ] [ Table 4 ]. This resulted in almost perfect agreement between the two observers in using both grading systems, with a slightly better result using the Zdichavsky et al. classification. However, both grading systems were reliable and were easily employed in the classification process.

Table 4

Landis and Koch Kappa interpretation system for statistical

Screw misplacement/complication rates

Our misplacement and early/late complications rates proved to be comparable to the lowest in the literature, showing that our free hand, fluoroscopically guided technique (without using CT guidance) remains safe and effective. Although, the overall misplacement percentage in the literature is low, this does not reflect the potential for neurological/other morbidity.

CONCLUSION

Free-hand pedicle screw placement techniques performed under fluoroscopic guidance remain safe and effective for spine stabilization in the lumbar region. For experienced surgeons, there was only a slight difference in results between conventional vs. computer-assisted techniques for accurate screws placement. We advocate the routine postoperative CT assessment of lumbar instrumented pedicle/screw fusions to allow for accurate confirmation of screw placement. The future introduction of a grading system to better facilitate decision making would be useful.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Aoude AA, Fortin M, Figueiredo R, Jarzem P, Ouellet J, Weber MH. Methods to determine pedicle screw placement accuracy in spine surgery: A systematic review. Eur Spine J. 2015. 24: 990-1004

2. Gelalis ID, Paschos NK, Pakos EE, Politis AN, Arnaoutoglou CM, Karageorgos AC. Accuracy of pedicle screw placement: A systematic review of prospective in vivo studies comparing free hand, fluoroscopy guidance and navigation techniques. Eur Spine J. 2012. 21: 247-55

3. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics. 1977. 33: 159-74

4. Tian N-F, Huang Q-S, Zhou P, Zhou Y, Wu R-K, Lou Y. Pedicle screw insertion accuracy with different assisted methods: A systematic review and meta-analysis of comparative studies. Eur Spine J. 2011. 20: 846-59

5. Zdichavsky M, Blauth M, Knop C, Graessner M, Herrmann H, Krettek C. Accuracy of Pedicle Screw Placement in Thoracic Spine Fractures: Part I: Inter- and Intraobserver Reliability of the Scoring System. Eur J Trauma. 2004. 30: 234-40

6. Zdichavsky M, Blauth M, Knop C, Lotz J, Krettek C, Bastian L. Accuracy of Pedicle Screw Placement in Thoracic Spine Fractures: Part II: A Retrospective Analysis of 278 Pedicle Screws Using Computed Tomographic Scans. Eur J Trauma. 2004. 30: 241-7

Abstract

Background:Dysembryoplastic neuroepithelial tumors (DNETs) are rare, benign brain neoplasms that typically arise in children and adolescents and classically present with intractable, partial complex seizures. DNETs are classically associated with a favorable prognosis after complete surgical resection.

Case Description:We describe a case of long-term recurrence of a DNET, which initially resected and diagnosed as an oligodendroglioma prior to the recognition of DNETs. This patient was seizure-free for 12 years and had no signs of radiologic progression until 24 years after initial resection. On repeat surgical resection, 31 years after the initial surgery, histopathologic evaluation identified the characteristic features of DNET in both specimens.

Conclusions:This patient's 24-year disease-free interval prior to radiologic recurrence demonstrates the longest interval to relapse in the literature for a DNET. This case illustrates the possibility of late recurrence of DNETs decades after radiographical complete resection to emphasize the necessity of thoughtful clinical judgment in adult survivors of low grade pediatric neoplasms who present with seizures after a prolonged seizure-free interval.

Keywords: Dysembryoplastic neuroepithelial tumor, low-grade glioma, recurrence

INTRODUCTION

First described in 1988,[ 3 ] dysembryoplastic neuroepithelial tumors (DNETs) are rare, benign brain neoplasms that typically arise in children and adolescents and classically present with intractable, partial complex seizures.[ 1 3 ] These well-circumscribed glial-neuronal neoplasms commonly arise within the supratentorial cortical gray matter, have a predilection for the temporal lobe, and usually do not demonstrate significant peritumoral edema, mass effect, or contrast enhancement on magnetic resonance imaging (MRI).[ 6 17 ] DNETs are histopathologically characterized as glial-neuronal neoplasms with intracortical, multinodular architecture and special glioneuronal elements including oligodendroglia-like cells, astrocytes, and well-differentiated “floating neurons.”[ 1 3 ]

DNETs are slow-growing benign neoplasms associated with a favorable prognosis after complete resection without subsequent radiation or adjuvant chemotherapy. In contrast to subtotal resection, gross total resection of DNETs appears to correlate with low recurrence rates and improved seizure control,[ 9 12 14 15 ] However, despite characterization as benign lesions, there have been reports of radiologically progressive lesions after gross total resection,[ 2 8 10 13 ] with recurrences after as long as 125 months.[ 6 ] We report a case of long-term recurrence of DNET, initially resected and misdiagnosed as an oligodendroglioma prior to the recognition of DNETs, and discuss its neuro-oncologic relevance. This case extends the reported time to recurrence.

CASE REPORT

In 1982, a 9-year-old right-handed Caucasian boy with no past neurologic history experienced a first-time grand-mal seizure and underwent neuroimaging, which demonstrated a mass lesion involving the right posterior parieto-occipital region. He subsequently underwent a reported gross surgical resection, which led to a diagnosis of low-grade oligodendroglioma. Postoperatively, the patient remained seizure-free for 12 years until age 21, when he began experiencing both simple and complex partial seizures 1–2 times monthly. He was placed on carbamazepine and gabapentin, and an MRI at that time was unrevealing for recurrent tumor.

From age 21 to 31, the patient underwent serial MRI scans every other year, each of which demonstrated a stable resection cavity with no disease recurrence when compared to prior examinations. In 2006, at age 33, the patient's surveillance MRI demonstrated a nonenhancing mass spanning the right parieto-occipital junction without peritumoral edema or mass effect, concerning for tumor recurrence in the resection cavity of the surgery 24 years prior. The patient elected to defer surgery and continue medical management of his epilepsy. Over the next several years, he continued to develop worsening seizures refractory to three antiepileptic medications. Surveillance MRIs demonstrated progressive nodular enhancement of the lesion [ Figure 1a ]. In 2013, at age 40, the patient was recommended intracranial monitoring to delineate his seizure focus, prior to tumor resection. He underwent stereo-electroencephalography, which revealed a seizure onset zone in cortex anterior and inferomedial to the recurrent lesion. The patient subsequently underwent gross total resection of the mass and adjacent seizure onset zone [ Figure 1b ].

Figure 1

Preoperative (a) and postoperative (b) T1-contrasted magnetic resonance imaging demonstrates nodular enhancement and subsequent complete resection of the nodule

Histopathological evaluation identified the characteristic features of DNET in both specimens [ Figure 2 ]. Although identical in many respects to the 1982 lesion, the 2013 lesion had areas with numerous granular eosinophilic bodies and scattered pleomorphic nuclei, features seen in other slow-growing gliomas such as pilocytic astrocytomas. There were no Rosenthal fibers. Areas of associated cortex were not normal appearing but were too fragmented to determine if there was cortical dysplasia. In the 2013 case, a Ki67 immunostain showed only rare positive cells. Fluorescence in situ hybridization studies were negative for 1p19q co-deletion. There were no mutations in IDH1, IDH2, or BRAF. MGMT promoter methylation was reported to be low. At the time of this report, the patient has been entirely seizure-free (ILAE Class I) for 24 months.

Figure 2

Hematoxylin and eosin (H and E) stained sections from 1982 at ×100 (a) show a round-cell glial lesion with microcystic features and myxoid change consistent with an oligodendroglioma. At ×400 (b), there are neurons floating in mucinous pools, a distinctive feature of dysembryoplastic neuroepithelial tumor (DNET) that was not identified until 1988. H and E stained sections from 2013 show almost identical features, now widely recognized as characterizing a DNET (c, ×100; d, ×400)

DISCUSSION

Since the initial study of a recurrent case in 2000,[ 7 ] there have been dozens of reports of DNET recurrence.[ 2 ] However, the great majority of these were initially incompletely resected.[ 2 10 13 ] Our patient's case represents an initial gross total resection, as verified by multiple surveillance MRIs, with in situ radiographic recurrence and ongoing progression after 24 years.

Seizure recurrence after gross total resection for DNET is not uncommon, and our patient developed seizures 12 years after his initial resection. Although complete resection of the tumor is sufficient to cure epilepsy related to DNET in many cases,[ 5 ] previous reports[ 6 ] of recurrence have suggested that seizures may begin postoperatively after a seizure-free interval without any evidence of radiographic progression, as initially occurred in our case. Indeed, neuroglial tumors frequently present with medically-refractory epilepsy associated with cortical dysplasia that may not be apparent on MRI,[ 16 ] indicating that surgical planning in the setting of tumor-related epilepsy should include not only consideration of the tumor but also the suspected seizure onset zone. In many cases, such as the one reported here, intracranial monitoring is indicated to define the seizure onset for inclusion in the resection in order to optimize chances for surgical cure of the patient's epilepsy.

Radiologic features of DNETs include hypointensity on T1-weighted MR images and hyperintensities on T2-weighted MR images whereas edema and mass effect are commonly absent.[ 4 11 ] These features can also be shared by diffuse astrocytomas and WHO grade II oligodendrogliomas. In our case, the patient's initial diagnosis was low-grade oligodendroglioma. Fortunately, we were able to obtain the original resection material from 31 years prior in an effort to compare the present histopathology with the initial resection. To the best of the authors’ knowledge, this patient's 24-year disease-free interval prior to radiologic recurrence represents the longest interval to relapse in the literature for a DNET.

This case highlights the necessity of thoughtful clinical judgment in patients who present with epilepsy after a prolonged seizure-free interval. DNET should be considered in the differential diagnosis for patients with long-standing epilepsy and tumor recurrence, particularly if they underwent surgical resections of neoplasms prior to the recognition of DNETs in 1988.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Bilginer B, Yalnizoglu D, Soylemezoglu F, Turanli G, Cila A, Topçu M. Surgery for epilepsy in children with dysembryoplastic neuroepithelial tumor: Clinical spectrum, seizure outcome, neuroradiology, and pathology. Childs Nerv Syst. 2009. 25: 485-91

2. Chao L, Tao XB, Jun YK, Xia HH, Wan WK, Tao QS. Recurrence and histological evolution of dysembryoplastic neuroepithelial tumor: A case report and review of the literature. Oncol Lett. 2013. 6: 907-14

3. Daumas-Duport C, Scheithauer BW, Chodkiewicz JP, Laws ER, Vedrenne C. Dysembryoplastic neuroepithelial tumor: A surgically curable tumor of young patients with intractable partial seizures. Report of 39 cases. Neurosurgery. 1988. 23: 545-56

4. Daumas-Duport C, Varlet P, Bacha S, Beuvon F, Cervera-Pierot , Chodkiewicz JP. Dysembryoplastic neuroepithelial tumors: Nonspecific histological forms – A study of 40 cases. J Neurooncol. 1999. 41: 267-80

5. Englot DJ, Berger MS, Barbaro NM, Chang EF. Factors associated with seizure freedom in the surgical resection of glioneuronal tumors. Epilepsia. 2012. 53: 51-7

6. Fernandez C, Girard N, Paredes AP, Bouvier-Labit C, Lena G, Figarella-Branger D. The usefulness of MR imaging in the diagnosis of dysembryoplastic neuroepithelial tumor in children: A study of 14 cases. AJNR Am J Neuroradiol. 2003. 24: 829-34

7. Hammond RR, Duggal N, Woulfe JM, Girvin JP. Malignant transformation of a dysembryoplastic neuroepithelial tumor. Case report. J Neurosurg. 2000. 92: 722-5

8. Jensen RL, Caamano E, Jensen EM, Couldwell WT. Development of contrast enhancement after long-term observation of a dysembryoplastic neuroepithelial tumor. J Neurooncol. 2006. 78: 59-62

9. Khajavi K, Comair YH, Wyllie E, Palmer J, Morris HH, Hahn JF. Surgical Management of pediatric tumor-associated epilepsy. J Child Neurol. 1999. 14: 15-25

10. Kim AH, Thompson EA, Governale LS, Santa C, Cahill K, Kieran MW. Recurrence after gross-total resection of low-grade pediatric brain tumors: The frequency and timing of postoperative imaging. J Neurosurg Pediatr. 2014. 14: 356-64

11. Kuroiwa T, Bergey GK, Rothman MI, Zoarski GH, Wolf A, Zagardo MT. Radiologic appearance of the dysembryoplastic neuroepithelial tumor. Radiology. 1995. 197: 233-8

12. Luyken C, Blümcke I, Fimmers R, Urbach H, Elger CE, Wiestler OD. The spectrum of long-term epilepsy-associated tumors: Long-term seizure and tumor outcome and neurosurgical aspects. Epilepsia. 2003. 44: 822-30

13. Maher CO, White JB, Scheithauer BW, Raffel C. Recurrence of dysembryoplastic Neuroepithelial tumor following resection. Pediatr Neurosurg. 2008. 44: 333-6

14. Nolan MA, Sakuta R, Chuang N, Otsubo H, Rutka JT, Snead OC III. Dysembrytoplastic neuroepithelial tumors in childhood: Long-term outcome and prognostic features. Neurology. 2004. 62: 2270-6

15. Paudel K, Borofsky S, Jones RV, Levy LM. Dysembryoplastic neuroepithelial tumor atypical presentation: MRI and diffusion tensor characteristics. J Radiol Case Rep. 2013. 7: 7-14

16. Santos MV, de Oliveira RS, Machado HR. Approach to cortical dysplasia associated with glial and glioneuronal tumors (FCD type IIIb). Childs Nerv Syst. 2014. 30: 1869-74

17. Yu AH, Chen L, Li YJ, Zhang GJ, Li KC, Wang YP. Dysembryoplastic neuroepithelial tumors: Magnetic resonance imaging and magnetic resonance spectroscopy evaluation. Chin Med J. 2009. 122: 2433-7

Abstract

Background:The authors report a case of fibrous encapsulation of the peritoneal catheter, which caused peritoneal shunt malfunction, and has not previously been researched well as a complication of peritoneal shunts.

Case Description:A 69-year-old woman who had undergone a lumboperitoneal (LP) shunt for communicative hydrocephalus following subarachnoid hemorrhage caused by a ruptured aneurysm was identified with malfunction of the LP shunt system by dementia and gait disturbance. Hydrocephalus was revealed on computed tomography (CT). Under a laparoscopy, the intraabdominal peritoneal catheter was observed to be obstructed by fibrous encapsulation covering it like a long white stocking. Although the fibrous encapsulating tissue was excised by laparoscopy forceps, a ventriculoperitoneal shunt device was replaced with a new peritoneal catheter. The histopathological diagnosis of the surgically resected encapsulating tissue was the fibrous tissue with a few inflammation cells and a layer of lining cells surrounding some part of it. In the immunohistochemical study, a layer of lining cells surrounding the fibrous tissue showed immunohistochemically positive staining for calretinin.

Conclusion:The fibrous encapsulation would be formed by peritoneal reaction to a peritoneal catheter as a foreign body by these histopathological and immunohistochemical analyses.

Keywords: Calretinin, fibrous encapsulation, laparoscopy, peritoneal catheter, peritoneal shunt, shunt malfunction

INTRODUCTION

Peritoneal shunt has been a standard procedure to treat hydrocephalus. Unusual peritoneal complications can occur, including an abdominal cyst or a pseudocyst that usually causes signs and symptoms of intraabdominal abnormalities, especially in babies or infants.[ 3 9 10 13 ] However, a fibrous capsule[ 6 12 ] or encapsulation of a peritoneal catheter has not been researched well as one of peritoneal complications. Herein, we report an adult case of fibrous encapsulation, which covered the intraabdominal peritoneal catheter like a long stocking and obstructed it under the laparoscope. Furthermore, the fibrous encapsulating tissue was pathologically and immunohistochemically examined and the potential mechanism of encapsulation was discussed.

CASE HISTORY

A 69-year-old woman had undergone lumboperitoneal shunt (LP) shunt for hydrocephalus caused by subarachnoid hemorrhage on January 14, 2016. During the LP shunt procedure, laparoscopic placement of the peritoneal catheter (Peritoneal Catheter with BioGlide®, Standard, Barium Stripe, Open Ended with 8 Wall Slits, 90 cm; Medtronic, Inc. Minneapolis, USA) into the peritoneal cavity was performed. Following LP shunt, symptoms caused by hydrocephalus in the patient disappeared. Three months later, she presented with dementia and gait disturbance in April, 2016. Hydrocephalus was diagnosed by computed tomography (CT) [ Figure 1a ]. LP shunt malfunction caused by obstruction of the peritoneal catheter was suspected. Although obvious obstruction of the peritoneal catheter could not be found by shuntgraphy, laparoscopy-assisted surgery was performed, and the intraabdominal peritoneal catheter was obstructed by a fibrous encapsulating tissue, which covered it like a long stocking [Figure 2a – c ]. This encapsulating tissue of the peritoneal catheter was excised by laparoscopy forceps [ Figure 2d ]. However, this peritoneal catheter was too short to be connected to a VP shunt valve on the skull, and a new peritoneal catheter was replaced into peritoneal cavity. Following VP shunt, the size of lateral ventricles became normal [ Figure 1b ] and the patient discharged without its neurological signs and symptoms on May 10, 2016. The histopathological diagnosis of this encapsulating tissue was the fibrous tissue with a few inflammation cells [ Figure 3a ]. Moreover, some parts of this fibrous tissue were surrounded by a layer of lining cells that showed immunohistochemically positive staining for calretinin [ Figure 3b ]. Therefore, the fibrous encapsulation obstructing the intraabdominal peritoneal catheter would be caused by foreign body reaction of peritoneum to a peritoneal catheter as a foreign body.

Figure 1

(a) CT on admission revealing the dilatation of bilateral ventricles and the bilateral periventricular lucency. (b) Postoperative CT revealing the size of bilateral ventricles was normalized and bilateral periventricular lucency disappeared after ventriculoperitoneal shunts

Figure 2

(a) The distal side of the peritoneal catheter is obstructed by a fibrous encapsulating tissue covering it like a long stocking. (b) The fibrous encapsulation covers the intraabdominal peritoneal catheter from the middle part of it to the distal side of it. (c) The fibrous encapsulating tissue disconnects with a fibrous tissue at the orifice of peritoneal cavity. (d) The fibrous encapsulating tissue is about 16cm long and it looks like a long white stocking

Figure 3

(a) Photomicrograph of the surgical specimen shows fibrous tissue with a few inflammatory cells. And it is covered with a layer of cells suspected to be mesothelium cells (and ←). Hematoxylin and eosin stain, original magnification ×200. (b) Immunohistochemical examination revealing that a layer of cells suspected to be mesothelium shows positive staining for calretinin in the current case. Immunohistochemical examination revealing that a layer of lining cells (c) and a few surface cells (and ↑) (d) also show positive staining for calretinin in previously reported fibrous capsule cases

DISCUSSION

Fibrous capsule formation of the end of a peritoneal catheter, which covered it like a stocking was first described in 1954 [ Table 1 ].[ 12 ] However, the precise difference between fibrous capsule and cyst was not pointed out. Later, the blockage of the tube within the abdominal cavity by either omentum or scar tissue was reported in 1955.[ 4 ] Fibrous encasement of the peritoneal catheter tip was described as one of the causes of shunt malfunction in 1983.[ 1 ] Under a laparoscope, the tip of the distal catheter ensheathed by adhesions and scar tissue was also observed and reported in 2007.[ 5 ] With the use of laparoscope, the author reported two cases of fibrous capsule formation of distal or end of a peritoneal catheter, which caused peritoneal shunt failure of VP shunts.[ 6 ] Furthermore, the fibrous encapsulation covering and obstruction of the intraabdominal peritoneal catheter is described in this case report. While the fibrous capsules cover a peritoneal catheter tip or its end like a stocking or sox [Figure 4a and b ], the fibrous encapsulation completely covers an intraabdominal peritoneal catheter like a long white stocking [ Figure 2d ]. However, fibrous capsule, encapsulation, scar tissue blockage, or fibrous encasement has not been researched well and still remains unknown.

Table 1

Cases of fibrous capsule or encapsulation of a peritoneal catheter

Figure 4

A white fibrous capsule like a sox (a) and a thin membranous fibrous capsule like a stocking (b) cover the end of the peritoneal catheter in the previously reported cases

A fibrous encapsulation or capsule covering the peritoneal catheter like a long stocking or sox obstructed a peritoneal catheter and caused hydrocephalus without signs and symptoms of intraabdominal abnormalities. On the other hand, the obstruction of distal catheter tip ensheathed by adhesions and scar tissue also caused hydrocephalus without abdominal complications.[ 5 ] Even though both of them caused obstruction of a peritoneal catheter, the adhesions and scar tissue were completely different from the fibrous capsules and encapsulation because they did not cover a peritoneal catheter like a stocking or sox under the laparoscope.

An abdominal cyst or a pseudocyst as an unusual peritoneal shunt complication usually has signs and symptoms of intraabdominal abnormalities in babies or infants.[ 3 9 10 13 ] They are supposed to be caused by frequent peritoneal infections or multiple laparotomies by shunt revisions.[ 3 10 13 ] In addition, they have been pathologically reported to be a thick or thin-walled fibrous tissue infiltrated by inflammatory cells.[ 3 10 13 ] However, the fibrous encapsulation of the current case or the fibrous capsules reported by the author[ 6 ] were not related to frequent peritonitis or frequent laparotomies by shunt revisions [ Table 1 ]. Furthermore, the fibrous encapsulation or fibrous capsules did not show such an inflammation in pathological study. From the clinical and histopathological features, the fibrous capsules and encapsulation are completely different from an abdominal cyst or pseudocyst, and should be discriminated from them.

The histopathological feature of the fibrous encapsulating tissue in the current case is a fibrous tissue with a few inflammatory cells, and some part of it are covered with a layer of lining cells supposed to be mesothelium cells [ Figure 3a ]. In addition, a layer of lining cells shows immunohistochemically positive staining for calretinin,[ 2 8 ] which is expressed in normal mesothelium [ Figure 3b ], although Calretinin is expressed in several normal tissues and several tumors.[ 2 ] One of the two fibrous capsules previously reported by the author[ 6 ] revealed the same histopathological and immunohistochemical feature as the fibrous encapsulating tissue in the current case [ Figure 3c ]. Although other reported fibrous capsule cases showed hyalinized and degenerated tissue, they also involved a few cells that were immunohistochemically positive for calretinin [ Figure 3d ]. Therefore, there would be a causal relation between fibrous capsule or encapsulation and peritoneum.

Interestingly, fibrous tissue at the orifice of the peritoneal cavity does not connect with fibrous encapsulating tissue [ Figure 2d ]. However, it might be possible that the fibrous encapsulating tissue would be broken and move to a distal side of peritoneal catheter by shuntgraphy, in which contrast medium was injected into a peritoneal catheter with relatively high pressure. The fibrous encapsulating tissue would entirely cover an intraabdominal peritoneal catheter in an abdominal cavity and connect with peritoneum at the orifice of abdominal cavity under a laparoscope. Peritoneal membrane may encapsulate a peritoneal catheter as a foreign body to protect peritoneal cavity. The fibrous encapsulating tissue might be broken, diminished in size, and turned into fibrous capsules because the results of histological and immunohistochemical investigations are almost the same.

The encapsulation of this current case was formed for only 3 months following LP shunt. One of the previously reported fibrous capsules was also formed for 5 months following VP shunt [ Table 1 ]. Although the other case of fibrous capsules was formed 11 years after VP shunt revision, this fibrous capsule had already been degenerated in its histological feature. Fibrous encapsulation or capsule might be formed soon after peritoneal shunt.

Occlusion of the peritoneal catheter tip was reported to appear in 9.5% of the cases among abdominal complications in VP shunt, even though CSF loculation or cyst formation appeared in 1.7%.[ 1 ] Such a fibrous capsule or encapsulation could not be found out without laparoscopy-assisted surgery. Such a fibrous capsule or encapsulation might be more common in the case of occlusion of the peritoneal catheter.

CONCLUSION

In conclusion, the fibrous encapsulation or capsule would be formed by peritoneal reaction to the peritoneal catheter as a foreign material according to the histopathological and immunohistochemical analyses. The fibrous encapsulating tissue would turn into a fibrous capsule. Laparoscopy can offer several advantages in placement or observation of a peritoneal catheter into peritoneal cavity.[ 7 ] Especially, with use of a laparoscope, the cause of malfunction of a peritoneal catheter can be precisely revealed.[ 11 ] Fibrous encapsulation is one of the causes of the occlusion of the peritoneal catheter. Because a fibrous encapsulation of a peritoneal catheter might be reformed again, periodic long-term follow-up medical check should be scheduled. Regarding the use of a laparoscope, further research is needed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Agha FP, Amendola MA, Shirazi KK, Amendola BE, Chandler WF. Unusual abdominal complications of ventriculo-peritoneal shunts. Radiology. 1983. 146: 323-6

2. Doglioni C, Dei Tos AP, Laurino L, Iuzzolino P, Chiarelli C, Celio MR. Calretinin: A novel immunocytochemical marker for mesothelioma. Am J Surg Pathol. 1996. 20: 1037-46

3. Fischer EG, Shillito J. Large abdominal cysts: A complication of peritoneal shunts. Report of three cases. J Neurosurg. 1969. 31: 441-4

4. Jackson IJ, Snodgrass SR. Peritoneal shunts in the treatment of hydrocephalus and increased intracranial pressure: A 4-year survey of 62 patients. J Neurosurg. 1955. 12: 216-22

5. Jea A, Al-Otibi M, Bonnard A, Drake JM. Laparoscopy-assisted ventriculoperitoneal shunt surgery in children: A series of 11 cases. J Neurosurg. 2007. 106: 421-5

6. Kano T. Fibrous capsule formation of the peritoneal catheter tip in ventriculoperitoneal shunt: Two case reports. Surg Neurol Int. 2014. 5: S451-54

7. Khosrovi H, Kaufman HH, Hrabovsky E, Bloomfield SM, Prabhu V, el-Kadi HA. Laparoscopic-assisted distal ventriculoperitoneal shunt placement. Surg Neurol. 1998. 49: 127-34

8. Lugli A, Forster Y, Haas P, Nocito A, Bucher C, Bissig H. Calretinin expression in human normal and neoplastic tissues: A tissue microarray analysis on 5233 tissue samples. Hum Pathol. 2003. 34: 994-1000

9. Parry SW, Schuhmacher JF, Llewellyn RC. Abdominal pseudocysts and ascites formation after ventriculoperitoneal shunt procedures: Report of four cases. J Neurosurg. 1975. 43: 476-80

10. Rainov N, Schobess A, Heidecke V, Burkert W. Abdominal CSF Pseudocysts in Patients with Ventriculo-Peritoneal Shunts: Report of Fourteen Cases and Review of the Literature. Acta Neurochir. 1994. 127: 73-8

11. Rodgers BM, Vries JK, Talbert JL. Laparoscopy in the diagnosis and treatment of malfunctioning ventirculo-peritoneal shunts in children. J Pediatr Surg. 1978. 13: 247-53

12. Scott M, Wycis HT, Murtagh F, Reyes V. Observations of ventricular and lumbar subarachnoid peritoneal shunts in hydrocephalus in infants. J Neurosurg. 1955. 12: 165-75

13. Yamashita K, Yonekawa Y, Kawano T, Ihara I, Taki W, Kobayashi A. Intra-abdominal cyst following revision of ventriculoperitoneal shunt – Case report. Neurol Med Chir. 1990. 10: 748-52

Abstract

Background:Various complications after ventriculoperitoneal (VP) shunt surgery have been reported, but peroral extrusion of peritoneal catheter is an extremely rare complication, and only 20 cases have been reported since 1987. The pathophysiology still remains unclear and the management is challenging.

Case Description:A 5-year-old boy presented with a catheter coming out of his mouth. The boy had a posterior fossa tumor surgery and had VP shunt insertion 1 year earlier. Clinical signs and imaging studies showed that the distal end of the catheter had perforated the gaster and migrated upward and extruded through the mouth. Emergency removal of the shunt and proper treatment were done and he made uneventful recovery.

Conclusion:Peroral extrusion of VP shunt is extremely rare. Clinicians should be aware of this complication. With early diagnosis and proper management, the prognosis for good recovery is excellent, with only two deaths being reported in the literature. Complication of shunt extrusion is difficult to avoid, but knowing the risk factors, pathophysiology and proper management will decrease the morbidity and mortality of such cases.

Keywords: Management, patophysiology, peroral extrusion, risk factors, VP shunt

INTRODUCTION

Ventriculoperitoneal (VP) shunt is the most widely used procedure to treat hydrocephalus.[ 19 ] VP shunt surgery is associated with a high rate of complications (24–47%), including infection, obstruction, cerebrospinal pseudocyst, bowel perforation, and shunt migration.[ 18 21 22 ] Bowel perforation, albeit rare, is a serious complication which can sometimes lead to a fatal outcome.[ 2 17 19 ] The incidence of bowel perforation is reported to be 0.1–0.7% of all peritoneal shunting procedure,[ 18 ] with the most common site of perforation being the colon (70%), followed by the stomach (16%) and small bowel (14%).[ 17 ] Extrusion of the peritoneal catheter occurred in about half of the cases of bowel perforation.[ 18 ] Extrusion of the catheter may occur in any natural orifices, the most common being through the anus (61.9%) or not at all (31.4%).[ 17 ] Cases with peroral extrusion of the peritoneal catheter is very rare, and most commonly associated with gastric perforation.[ 5 ] We describe here a case report and review of the literature for all reported cases of peroral extrusion of a VP shunt catheter. To our knowledge, there were 21 cases of peroral extrusion of the peritoneal catheter that have been reported in the literature since 1987, including the present case.

CASE HISTORY

A 5-year-old boy presented with peroral extrusion at the distal end of a VP shunt catheter. The boy had been diagnosed by magnetic resonance imaging as having posterior fossa tumor and hydrocephalus when aged 4 years. A surgery was performed and VP shunt catheter was inserted using a Chhabra-slit-in-spring silicone shunt system. After the surgery, the patient remained well with the exception of mild gait disturbance. One week before admission to our hospital, the boy complaint of upper abdominal discomfort with emesis. In the following day, he regurgitated and severed peritoneal catheter exiting through the mouth.

Examination

At the time of admission, the boy was afebrile and fully conscious. We found no evidence of meningitis or increased intracranial pressure. The abdomen was soft and bowel sounds were normal. There was no sign of inflammation along the shunt tract. The peritoneal catheter was found extruding from his mouth [ Figure 1 ]. There was no flow of cerebrospinal fluid (CSF) from the end of the catheter, which meant that an obstruction had occurred in the shunt catheter system. Laboratory results indicated no evidence of infection or any other abnormality. Head computed tomography scan showed no enlargement of the ventricles and the ventricular catheter was in proper position [ Figure 2a ]. Skull X-ray showed the peritoneal catheter coming up through the pharynx and extruded through the mouth [ Figure 2b ]. Chest X-ray revealed the migration of the peritoneal catheter into the stomach and esophagus [ Figure 3 ].

Figure 1

Pretreatment photograph during intubation

Figure 2

Anteroposterior and lateral films of the skull showing the position of the ventricular catheter (a) and the presence of the distal catheter in the pharynx and mouth (b)

Figure 3

Chest film showing the upward migration of the distal catheter into the stomach and esophagus

Treatment

The boy underwent emergency shunt removal. During intubation the distal catheter was seen coming out of the esophagus. Surgical incision was made in the previous scar in the scalp and in median abdomen. The distal catheter was cut at the abdomen site before entering the peritoneal cavity. The ventricular catheter was disconnected from the chamber, and there was a flow of CSF from the ventricular catheter. Analysis of the CSF did not reveal any sign of infection. The ventricular end and the chamber were removed through the scalp incision, and part of the distal catheter under thoracic tract was removed through the median abdomen incision. The distal catheter in peritoneal cavity, which had perforated the stomach wall, was removed easily by pulling out through the opening of the mouth. We removed the whole catheter and observed the patient for 3 days. External drainage was not performed. The boy was nil peroral and maintained on intravenous fluids and antibiotics for 3 days. During the observation there was no sign of meningitis or peritonitis. There was no signs and symptoms of increased intracranial pressure, which meant the boy had become shunt independent, thereby no replacement shunt system was required. After 5 days of treatment, the boy was discharged in satisfactory condition and is currently doing well.

DISCUSSION

We conducted literature search of all cases of peroral extrusion of a VP catheter shunt via PubMed and MEDLINE, and identified 20 cases (excluding the present case) of peroral extrusion of a VP shunt catheter, which are summarized in Table 1 . Eleven (52.4%) patients are females and 10 (47.6%) are males; 19/21 patients (90.5%) are children aged below 12. The mean patient age is 7 years and 5 months. The youngest patient age documented is 8 months old and the oldest is 47 years old. Duration between catheter placement and peroral extrusion range from 3 months to 10 years. Most of the major complaints was vomiting in 11 (52.38%) cases, shunt out of the mouth suddenly in 4 (19.04%) cases, abdominal pain in 1 case, and also respiratory distress in 1 case with a perforation of the trachea. Perforation site is the gaster in 15 (71.42%) cases, jejunum in 1 (5%) case, gastroesophageal junction in 1 (5%) case, trachea in 1 (5%) case, and the rest (19%) is unidentified probably because no open surgery or no good radiological study to visualize or predict the site of perforation was performed. Outcome is more favorable when there is no accompanying CSF infection or peritonitis. Peritonitis and meningitis markedly increase mortality rate.[ 5 ] According to our literature review, all patients are alive including the present case except for two cases where both had an accompanying CSF infection.

Table 1

Summary of the literature review of cases with peroral extrusion of a ventriculoperitoneal shunt catheter

Pathophysiology

According to our case literatures review, all had a delayed presentation, which meant that the perforation is caused by a chronic process rather than acute injury (e.g., during the procedure). An important part of the pathophysiology of perforation is local inflammation and repeated pressure on the bowel wall. Inflammation leads to formation of an encasing fibrosis, which anchored the catheter to the serosal surface of the bowel wall. The site of catheter adherence to the bowel wall is then subjected to repeated pressure, due to the “pushing” effect of intestinal movements,[ 6 ] leading to the development of ulcer, and eventual perforation.[ 18 19 ] Bowel perforation may or may not lead to extrusion of the catheter, whereas when it did occur, mostly with downward migration that occur in accordance to direction of normal peristalsis, upward migration and extrusion through the oral orifice is very rare. Peroral extrusion of the catheter required it to move retrogradely against normal peristaltic movement across the gastroesophageal junction toward the oral cavity, which may be due to abnormal peristalsis[ 8 ] or bulk movement upwards caused by repeated vomiting episodes.[ 1 ] Sites of perforation also occurred in the upper part of the gastrointestinal system. From the literatures report, found in nearly all cases, site of perforation occurred in gaster; only two cases with unusual site of perforation is in the trachea and in the jejunum. In cases of perforation of the trachea, it is quite interesting because the catheter penetrates the diaphragm, enter the thoracic cavity, and finally into the trachea. The most distal perforation site of the gastrointestinal tract in oral extrusion cases is jejunum. In case of jejunum perforation, physiologically, the catheter should be pushed downward in accordance to the intestinal peristalsis. This phenomenon could be because of the position and direction of catheter penetration and decrease of peristalsis that leads to contra-mechanism movement, thereby resulting in upward migration. In our case, based on the radiological results, perforation is in the gaster as reported in most cases, with migration and peroral extrusion have been occurred.

Risk factors

The etiology of migration and extrusion of a VP shunt catheter has not been fully understood. From the literatures that we have reviewed, we identified the risk factors associated with extrusion of the peritoneal catheter and divided them into internal (ensuing from the host) and external factors. Internal factors include: (1) age, (2) nutritional status, (3) bioreactivity, (4) previous abdominal surgery and (5) chronic immobilization. Younger age has been mentioned as a prominent risk factor for bowel perforation in much literatures,[ 17 18 20 ] with children aged 10 years or less constituting 70.1% of bowel perforation cases and the male to female ratio is 3:2.[ 17 ] Plausible theory for this occurrence might be because children had weaker bower musculature and more vigorous peristaltic activity.[ 18 ] Organ penetration by catheter is also facilitated by malnutrition.[ 8 ] Out of the cases we reviewed, 3/21 (14.3%) patients presented with malnutrition.[ 1 8 10 ] Malnutrition may also occur as a result of recurrent emesis caused by the presence of the peritoneal catheter in the esophagus and gaster. Bioreactivity, such as silicon allergy[ 3 ] or mechanical irritation of the bowel wall by the catheter tip,[ 1 14 ] subsequently leads to local inflammation and perforation. Scarring or adhesion from previous abdominal surgery has been mentioned as a risk factor.[ 2 8 ] Two reported cases (9.5%) had history of previous abdominal surgery.[ 11 14 ] Three (14.3%) cases presented with myelomeningocele,[ 2 5 15 ] which has been suggested as a risk factor for bowel perforation due to neurogenic weakness of the bowel wall. In our case, age factor seems to be a very influential factor on the occurrence of perforation and migration of shunt tube.

External factors include: (1) surgical error, (2) infection, (3) shunt type, and (4) shunt length. Perforation caused by surgical error is mainly associated with an acute presentation, which was not shown in any of the cases we reviewed. Surprisingly, from our review of the literature, no cases presented clinically with peritonitis, and 2 out of 21 (9.5%) presented with CSF infection, which led to a grave outcome as both patients are deceased. A proposed explanation for the low number of infection is a protective mechanism by the fibrous encasement of the catheter which prevented extension of infection from the bowel to the peritoneal cavity. Then again, many of the cases we reviewed have gaster as the site of perforation, which had a lower number of bacterial colonization compared to other sites of the bowel, such as the colon. Infection of the shunt tract itself may contribute through a mechanism which is similar to silicone allergy or mechanical irritation, eventually leading to local inflammation by means of foreign body reaction.[ 14 18 ] Stiff, hard tipped, sharp, long, or spring coiled type of catheter has been associated with increased bowel perforation risk.[ 1 5 17 18 19 ] However, the rigid and hard catheters are not the only cause. From the literature, it was observed only two (9.5%) cases used Raimondi coil spring catheter,[ 4 8 ] five (23.8%) cases (including the present case) used Chhabra-slit-spring silicone catheter,[ 5 7 10 17 ] and one (5%) case used Holter valve with soft tube.[ 6 ] The rest did not mention the type of shunt that was used. Longer distal catheter length is also mentioned as a risk factor.[ 14 ] In our case, there were no signs of abdominal infection or CNS infection. We also use a soft silicone shunt that is relatively safe against perforation of the abdominal organ. The time of the incident is also one year after surgery, so the surgical error factor can be eliminated.

Management

From the literature we have reviewed, our recommendation for the principles of treatment for shunt catheter perforation with peroral extrusion is: (1) emergency removal, (2) appropriate antibiotic therapy, (3) nil per oral, (4) reinsertion (if necessary). Emergency removal can be performed by open laparotomy, endoscopy, or pulling the catheter manually through the mouth. Earlier cases tend to choose open laparotomy as a method of removal, because laparotomy aided in visualization of any opening in the bowel caused by perforation that might need primary closure.[ 17 ] However, many authors suggested that invasive procedures such as laparotomy are not necessary because any opening in the bowel caused by perforation is small and should seal off spontaneously.[ 18 ] Before removal, the proximal and distal part of the catheter is divided, and then the proximal part is externalized or removed while the distal part is removed either through the extrusion site or proximally through the site of division. Disconnecting the ventricular from the peritoneal catheter further decreased the chance of infection, because there is no contact of the contaminated tube with neither the peritoneum nor the shunt tract.[ 1 ] Kothari[ 12 ] performed removal of the shunt through an incision behind the ear, which is not recommended, because of possibility of contamination from pulling the distal catheter through the peritoneal cavity.[ 16 18 20 ] Recently, minimally invasive laparoscopy has replaced laparotomy in cases of bowel perforation. Mandhan[ 15 ] did upper gastrointestinal endoscopy to assess entry point of the perforating catheter, then proceeded with laparoscopy to remove it. Pulling the distal catheter through the mouth has been the most frequent option of removal in the cases we reviewed. Pulling the catheter through the mouth is also the choice of removal management in our case. We postulated that the fibrous encasement surrounding the catheter play a role in sealing off the perforation site, which occurs when pull through is performed. In our opinion, an open laparotomy is indicated if there are signs of peritonitis, failed or was detained when pulling through or acute injury following improper operating procedures.

Infection control is an important part of the management of this complication. Our case emphasizes the importance of confirming early presence of infection. Broad spectrum antibiotics that cover the intestinal flora should be started at the time of admission. The risk of contamination during removal of the catheter should be minimized, by performing removal of the catheter with minimally invasive procedure and under antibiotic cover.[ 21 ] Postop antibiotics should also be given as prophylaxis.

Keeping the patient nil per oral is necessary for the healing process in bowel perforation cases. Recommendation for nil per orally management in our case is three days for recovery of the bowel. Several previous reports, recommendations for fasting after treatment vary greatly, mostly between 2 and 4 days.[ 1 9 10 13 16 21 ] In two cases, fasting lasted until 7 to 14 days.[ 5 18 ] All the literatures reported that no abdominal problems occurred posttreatment.

The patient might not need a replacement shunt because they might have become shunt independent, probably because their CSF pathway has already healed from the time of shunt placement or the primary cause has been corrected.[ 21 ] This is shown in our patient, because he showed signs of catheter obstruction but no sign of increased intracranial pressure. It can be concluded that he had become shunt independent. If the patient is asymptomatic after his shunt is removed, then he probably does not need shunt reinsertion.

Outcome

From the literature we get on the case of VP shunt complications with peroral extrusion; almost all the outcome is good. Only two cases of deaths were reported as a result of complication of meningitis. With proper management, the case could provide an optimal outcome with minimal morbidity.

CONCLUSION

Upward migration and peroral extrusion of VP shunt is extremely rare. Clinicians should be aware of this complication with early diagnosis and proper management. The best management should be emergency shunt removal by pulling the distal catheter through the mouth and prevention of ascending infection. In most of the cases, the prognosis for good recovery is excellent, with only two death being reported in the literature. The mortality cases were associated with complication of meningitis. Complication of shunt extrusion is difficult to avoid, but knowing the risk factors, pathophysiology and proper management will decrease the morbidity and mortality of such cases.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

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2. Berhouma M, Messerer M, Houissa S, Khaldi M. Transoral protrusion of a peritoneal catheter: A rare complication of ventriculoperitoneal shunt. Pediatr Neurosurg. 2008. 44: 169-71

3. Brownlee JD, Brodkey JS, Schaefer IK, Mostello L, Robson M, Heggers J. Colonic perforation by ventriculoperitoneal shunt tubing: A case of suspected silicone allergy. Surg Neurol. 1998. 49: 21-4

4. Danismend N, Kuday C. Unusual complication of ventriculoperitoneal shunt. Neurosurgery. 1988. 22: 798-

5. Dua R, Jain R. Peroral extrusion of ventriculoperitoneal shunt: A case report and review of the literature. Cent Eur Neurosurg. 2011. 72: 107-8

6. Fermin S, Fernández-Guerra RA, Sureda PJ. Extrusion of peritoneal catheter through the mouth. Childs Nerv Syst. 1996. 12: 553-5

7. Ghritlaharey RK. Review of the Management of Peroral Extrusion of Ventriculoperitoneal Shunt Catheter. J Clin Diagn Res. 2016. 10: PE01-6

8. Griffith JA, DeFeo D. Peroral extrusion of a ventriculoperitoneal shunt catheter. Neurosurgery. 1987. 21: 259-61

9. Gupta M, Digra NC, Sharma N, Goyal S, Agrawal A. Peroral extrusion of the peritoneal catheter in an infant. N Am J Med Sci. 2012. 4: 290-1

10. Gupta R, Mala TA, Gupta A, Paul R, Malla SA, Gupta AK. Transoral migration of peritoneal end of ventriculoperitoneal shunt with perforation of gastro-esophageal junction: A case report of a rare complication. Bangladesh J Med Sci. 2014. 13: 492-5

11. Jiménez Moya A, Penela Vélez De Guevara T, Gracia Remiro R, Romero Escós D, Santana Rodríguez C, Reig Del Moral C. Extrusion of a ventriculoperitoneal shunt catheter through the mouth. An Esp Pediatr. 2001. 54: 609-10

12. Kothari P, Shankar G, Kulkarni B. Extruded ventriculo-peritoneal shunt: An unusual complication. J Indian Assoc Pediatr Surg. 2006. 11: 255-6

13. Kundal VK, Gajdhar M, Sharma C, Agrawal D, Kundal R. Wandering distal end of ventriculoperitoneal shunt: Our experience with five cases and review of literature. J Nepal Paediatr Soc. 2013. 32: 266-9

14. Low SW, Sein L, Yeo TT, Chou N. Migration of the abdominal catheter of a ventriculoperitoneal shunt into the mouth: A rare presentation. Malays J Med Sci. 2010. 17: 64-7

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16. Murali R, Ravikumar V. Transoral migration of peritoneal end of ventriculoperitoneal shunt: A case report of a rare complication and review of literature. J Pediatr Neurosci. 2008. 3: 166-8

17. Odebode TO. Jejunal perforation and peroral extrusion of a peritoneal shunt catheter. Br J Neurosurg. 2007. 21: 235-6

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19. Sathyanarayana S, Wylen EL, Baskaya MK, Nanda A, Bando Y, Manabe Y. Spontaneous bowel perforation after ventriculoperitoneal shunt surgery: Case report and a review of 45 cases. Surg Neurol. 2000. 54: 388-96

20. Sinnadurai M, Winder MJ. Silicone spaghetti. J Clin Neurosci. 2009. 16: 1348-50

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22. Yilmaz MB, Egemen E, Tonge M, Kaymaz M. Transoral protrusion of a peritoneal catheter due to gastric perforation 10 years after a ventriculoperitoneal shunting – Case report and review of the literature. Turk Neurosurg. 2011. 23: 285-8

Abstract

Background:The People's Republic of China (PRC) has the highest incidence of neural tube defects (NTDs) in the world. NTDs remain a significant contributor to the global burden of disease amendable to surgical care; however, no studies to date have evaluated the patients’ perspective regarding perceived barriers to care.

Methods:The study was conducted at the Shanghai Children's Medical Center (SCMC) between 6/11/2014 and 7/17/2014. Surveys were administered to families presenting to the clinic of the SCMC director for Pediatric Neurosurgery. Additionally, orphaned patients under the care of the Baobei Foundation were surveyed for comparison. Participants were allowed to mark as many barriers on the survey as they deemed relevant to their experience.

Results:A total of 69 patients were surveyed. The most frequently chosen barrier to care, with a P value -5, was that the referring physician did not know enough about the child's condition. As compared to the Baobei Foundation orphans, surveyed patients presented at an older age for initial treatment (7 months versus 1 month, P value = 0.001), and visited more hospitals before reaching SCMC (3.14 versus 1.0, P value -5).

Conclusions:The results of this study highlight the referring physician as a primary barrier to care. The younger age at time of treatment for Baobei orphans born with NTDs supports this finding, as they essentially bypassed the referral process. An elaboration on reasons for this real or perceived barrier may provide insight into a means for expedited diagnosis and treatment of NTDs within the PRC.

Keywords: Barriers to care, neural tube defect, People's Republic of China, referral system, surgery, survey

INTRODUCTION

The People's Republic of China (PRC) has the highest incidence of neural tube defects (NTDs) in the world.[ 39 ] NTDs result from failure of the neural tube to close completely during embryogenesis and comprise a broad spectrum of disease processes encompassing certain cranial defects (e.g., anencephaly and encephalocele), open spinal dysraphism (e.g., meningocele and myelomeningocele), and closed spinal dysraphism (e.g., spinal lipoma and tight filum terminale).[ 11 15 ] To its credit, the PRC has implemented sweeping healthcare reforms in recent years, including maternal folic acid supplementation programs that have resulted in declining NTD rates.[ 5 27 39 ] Nevertheless, NTDs remain a significant public health concern with certain regions within the PRC having an incidence four times that seen in the United States.[ 27 35 ]

The more severe manifestations of NTDs demand medical attention within the first 24–72 hours of life for ideal long-term neurologic function.[ 19 32 ] Without treatment, neurologic impairment can be significant, resulting in large disability-adjusted-life-years (DALY).[ 9 ] Though the proper treatment of NTDs remains a complicated topic, often, early surgical intervention is warranted. As such, NTDs remain a significant contributor to the global burden of disease amendable to surgical care.[ 12 17 21 ] Low- and middle-income countries (LMIC) carry the majority of this weight, with an estimated reduction in global disease burden of 76% should surgical coverage in LMICs achieve levels similar to those seen in high-income countries.[ 12 ]

Access to surgical care for NTDs remains a broad subject that has not been extensively addressed in the literature. To date, the evaluation of barriers to timely surgical treatment has come primarily from retrospective institution-based analysis of gaps in care.[ 21 ] This approach fails to consider the patients’ and patient families’ perspective regarding perceived barriers to treatment. Thus, the aim of this study is to investigate the barriers to surgical care for NTDs from the patient perspective, thereby expanding the debate concerning global barriers to surgical care by considering relevant cultural factors.

We had the opportunity to explore this issue at the Shanghai Children's Medical Center (SCMC), a tertiary care hospital in the PRC with one of the country's premiere neurosurgical units. Those surveyed presented to SCMC through one of two primary routes: either as patients with their family member(s) or as orphans through the assistance of the Baobei Foundation, a horizontal program orchestrating the medical care of children in the PRC orphanage system. SCMC coordinates care for children from a wide geographic range centered in eastern China and, given its diverse patient population, represents an ideal location to ascertain the perceived barriers to surgical care for both of these groups.

MATERIALS AND METHODS

Study setting and participants

The study was conducted at SCMC, one of the premiere tertiary care centers for neurosurgery in the PRC. Study participants were the birth or foster parents of children presenting to the office of the director for Pediatric Neurosurgery at SCMC, Nan Bao, MD for treatment of a NTD between the dates of 6/11/2014 and 7/17/2014. Given that Dr. Bao was seeing patients in differing stages of the treatment process, patients surveyed in a single day included those presenting to the clinic for the first time, those presenting for the operation itself or those in various stages of postoperative follow-up. Regardless of the stage of treatment a patient was in, anyone presenting during the study timeframe was considered eligible for the survey.

Additionally, patients presenting under the care of the Baobei Foundation, who were similarly at various stages of their treatment, were considered eligible participants. The Baobei Foundation orphans who were seen at SCMC prior to the 6/11/2014 start date and who had thorough documentation were also eligible for study inclusion, given that the chief of the foundation who coordinated the care of these prior patients was available for interview.

Survey design

A barriers to care survey was created with the assistance of an UCLA-based focus group consisting of Chinese immigrants from both rural and urban areas of the PRC in order to design a culturally relevant survey.

Survey administration

All surveys were administered in a room adjoining Dr. Bao's clinic after proper parental or guardian verbal consent was obtained. Participants were not paid for their participation and it was emphasized that their participation or lack of participation would in no way affect the quality or type of care received at SCMC. The interviewers were two MD candidates at the David Geffen School of Medicine, UCLA with graduate-level training in qualitative methods. A bilingual hospital staff member aided the interviewers in the survey administration. After providing written consent, all participants completed baseline demographic information in addition to a barrier to care questionnaire. The questionnaire consisted of a list of preformed options and participants were permitted to mark as many barriers as they deemed relevant to their experience, including an “other” option where they could elaborate on barriers not contained within the original list. Participants could refuse to answer any questions deemed too sensitive or intrusive. The questionnaire in English is presented in Figure 1 . The families answered a version of the survey translated into Mandarin. An adjusted barrier to care survey was developed for children presenting to SCMC under the care of the Baobei Foundation and this is presented in Figure 2 .

Figure 1

Survey administered to families presenting to SCMC for NTD treatment, translated from Mandarin

Figure 2

Adjusted survey administered to BaoBei Foundation employees caring for orphans presenting to SCMC for NTD treatment, translated from Mandarin

Statistical analysis

The median length of time from birth to initial medical treatment was calculated for both the patients who presented with their families and for patients who presented through the Baobei Foundation. The significance in the difference between the median lengths of time for the groups was calculated using the bootstrapping method, given the non-Gaussian distribution of the data. Similarly, the significance in the difference between the median numbers of hospitals visited by each group was calculated using the bootstrapping method.

Additionally, the barriers to care options on the survey were numbered 1–14 and bootstrapped to calculate the frequency with which each barrier was selected by patients and families. In so doing, any potential correlation between barriers (e.g., barriers 1 and 2 being linked and chosen together more often than by chance alone) was accounted for, since each family's barrier choices were sampled as a unit as opposed to individually.

To evaluate for any correlation between the type of NTD diagnosed and the perceived barriers to care, a Fisher's exact test was performed, given the relatively small sample sizes within certain groups. In so doing, significance deviation from the null hypothesis could be calculated exactly. The Fisher's exact test was also used to evaluate for significant differences in malformation detection rates by referring physicians with respect to the type of NTD diagnosis.

RESULTS

Over a 6-week period, a total of 69 families were interviewed. The patients came from 14 provinces in addition to the city of Shanghai itself, with the furthest province being 2277 km from Shanghai. The number of patients presenting from each province are presented in Figure 3 and the population distribution in those represented provinces are presented in Figure 4 . Of the 69 families interviewed, six different types of NTDs were recorded and these are listed with their respective frequencies in Table 1 , separated according to closed versus open spinal dysraphism. Among those 69 families, two patients presented with both a spinal lipoma and tight filum terminale. Thus, a total of 71 diagnoses were seen.

Figure 3

Patient distribution by province as a percentage of the total number of families interviewed at SCMC

Figure 4

Population distribution by province as a percentage of the total population of the PRC

Table 1

Final patient diagnosis

Of the 71 diagnoses seen, 36 reported that the referring physician noted an abnormality at or before the time of birth, 33 reported that the physician did not note any abnormality at or before the time of birth, and two were uncertain when the abnormality was noted. This data is presented in Table 2 , divided between the different NTD types. Of the 36 families, who reported an abnormality noted at birth, 29 did not receive a NTD diagnosis from the physician at the time of birth, while seven did receive a NTD diagnosis from the physician at the time of birth. Again, this data is presented in Table 2 , divided between the different NTD types. Concerning the referring physician detection rate of specific malformations at the time of birth, myelomeningocele was detected significantly more often by the referring physician than tight filum terminale or tethered cord, with a P value of 0.005 and 0.036, respectively. Otherwise, the detection rates by the referring physicians at the time of birth did not vary significantly between groups.

Table 2

Patient sex, abnormality detection rate, and NTD detection rate by the referring physician at the time of birth

Among the 69 families, 18 children received some form of medical intervention related to their NTD or the sequelae of their disease prior to their arrival at SCMC. Four of the 18 children received two separate medical interventions prior to SCMC, amounting to a total of 22 interventions. The types of interventions recorded and their relative frequencies are presented in Table 3 .

Table 3

Reported frequency of medical interventions prior to patient arrival to SCMC

Additionally, each family was asked how they eventually heard about SCMC. All families except for one were willing to answer the question and six families chose two different options, for a total of 74 responses. The results are presented in Table 4 . Of the families who selected “other,” two specified that they were employees of SCMC, seven specified that they had lived, worked or gone to school in Shanghai, and had a general knowledge of the hospitals in the area, one specified that a taxicab driver within Shanghai recommended the hospital, and one specified that a third party financing the child's healthcare directed them to SCMC.

Table 4

Reported means of SCMC discovery

Regarding the different barriers to care for families, the most frequently chosen barrier, with a P value < 10^-5, was that the referring physician did not know enough about the child's condition (options #4). The second most frequently chosen option, with a P value of 0.070, was that the physician did not know to refer to SCMC (option #13). When comparing the most frequently chosen barriers to care between different NTD types (i.e., spinal lipoma versus meningocele, etc.), the only group with a particular barrier chosen significantly more than any other group was lipomyelomeningocele. The families of patients with lipomyelomeningocele indicated on the survey that the patient was receiving alternative treatments (option #12) significantly more frequently than the other NTD groups, with a P value of 0.041. The overall frequency with which various barriers to care were selected by the different NTD groups is presented in Table 5 .

Table 5

Frequency of family-reported barriers to surgical care

Among the Baobei Foundation orphans, 11 were identified as having been treated for a NTD, six of whom were male and five of whom were female. Ten of these patients were eventually diagnosed with myelomeningocele and one was diagnosed with meningocele. Survey data from patients presenting to SCMC with their families was compared to the data from patients presenting through the Baobei Foundation and two significant differences were found. First, the median age at initial treatment for the Baobei Foundation orphans was 1 month (ranging from 4 days to 5 months) and for children presenting with their families was 7 months (ranging from immediately after birth to 17 years), with a significant difference in the medians of P = 0.001. Second, the median number of hospitals visited (including SCMC) by the Baobei Foundation orphans was 1.0, while the median number of hospitals visited by children with their families was 3.14, a P value < 10^-5.

DISCUSSION

Families seeking NTD treatment for their children had a less direct route to appropriate surgical care than children in the PRC orphanage system, as evidenced by a median of six additional months to time of treatment, and a median of two additional hospitals visited before SCMC, as compared to PRC orphans. Parents identified the referring physician(s) as the primary impediment to surgical care, either because they perceived the physician had an inadequate understanding of the disease process or because the physician missed an opportunity to refer to SCMC for further evaluation. Comparatively, PRC orphans experienced expedited medical care. The primary difference in their healthcare experience lies in the Baobei Foundation, a horizontal program whose members have well-established connections with physicians in urban-based tertiary medical centers. Using these relations, the Baobei employees coordinate with the orphanages so that they are immediately alerted to the health issues of any new arrivals and arrange their expedited delivery to appropriate tertiary care. Thus, delayed initial diagnosis and referral, the primary issues faced by the surveyed families, were effectively mitigated as significant barriers to surgical care for the PRC orphans.

To understand the primary barriers faced by one of these families, one must consider the position of the referring physicians. Appropriate management of patients with NTDs can be consolidated to three primary tasks: adequate prevision of preventative measures to the mother, accurate diagnosis of the disease should a NTD develop, and appropriate referral of the patient should the hospital not possess adequate means of treatment. Each of these areas has the potential to contribute to the parent's perceived barriers and each will be addressed subsequently.

In recent years the Chinese government has instituted sweeping healthcare reforms that have had a large effect both in the urban and rural settings.[ 2 ] Among these reforms was the institution of a national folic acid supplementation program wherein all women with a rural household registration were provided folic acid supplements free of charge. The result of this government outreach was staggering, with a reported 22.4% drop in NTD prevalence in rural areas over a 2-year period.[ 5 27 39 ] However, over 50% of women utilizing folic acid supplements were doing so after they had discovered that they were pregnant, which is past the point of neural tube formation and is generally considered too late to prevent NTD formation.[ 16 ] Thus, despite the successes of this nationwide program, further maternal counseling is obviously required.

If a NTD does form in utero, the accurate diagnosis of the malformation is the referring physician's second hurdle. In the United States, the prenatal screening and diagnosis of NTDs is well established, with low-risk pregnancies being offered NTD screening in the form of a maternal serum alpha-fetoprotein (MSAFP) measurement at 16-18 weeks gestation or receiving a screening ultrasound at 18–20 weeks gestation. Characteristic findings on ultrasound are the backbone of the prenatal diagnostic process, should screening prove positive.[ 7 10 11 ] Despite its critical role in the prenatal diagnosis of NTDs, ultrasound detection rates remain highly variable, due in part to factors such as the size and location of the defect, the fetal position, the timing of diagnosis, maternal habitus, the available equipment, and the skill of the sonographer.[ 26 28 29 30 ] Several Western studies analyzing prenatal detection rates of major malformations found overall rates ranging from 22% to 50% for first trimester ultrasounds and 47% to 95% for second trimester ultrasounds.[ 1 4 8 18 30 ] While the PRC has extended genetic testing and prenatal screening techniques, such as ultrasound, to every pregnant woman in developed regions, proper ultrasound training in NTD detection appears to be lacking in rural areas of the PRC, where rates remain the highest.[ 18 37 ] The detection of NTDs via first and second trimester ultrasound in these rural communities was 15.6% and 49.6%, respectively, with the former percentage being below the above range reported in western countries, and the latter approaching the low end of the range.[ 18 ]

The final task of the referring physician is to know when and where to refer the patient once the diagnosis has been made. The World Health Organization's 2012 service delivery profile of the PRC touched briefly on this topic by commenting on the segmentation of the health information system and the lack of a standardized nationwide referral protocol.[ 34 ] A recent article expounded on knowledge sharing (KS) between healthcare facilities within the PRC by identifying four KS barrier themes: interpersonal trust, communication, hospital management, and inter-institutional.[ 38 ] Interpersonal trust barriers were founded on issues such as a lack of acquaintance between healthcare providers and a lack of trust towards medical information produced by other facilities. Communication barriers resulted from the lack of a digital means for transferring patient information and the lack of trust between healthcare providers making informal KS via phone or email, unlikely. Hospital management barriers stemmed from a lack of specific hospital requirements for KS and the absence of in-hospital staff for coordination purposes. Finally, inter-institutional barriers resulted from a paucity of national and local government policy on the topic.[ 38 ] The frequency with which referral to SCMC was seen as a barrier to care in our survey supports the existence of these KS issues among PRC hospitals.

Of note, defects with characteristically more obvious findings at birth (e.g., myelomeningocele) had significantly higher detection rates by referring physicians compared to defects with more inconspicuous features (e.g., tight filum terminale and tethered cord).[ 14 23 31 ] Despite these differences, families who received a timely diagnosis still identified the referring physician as a primary barrier to care. Certainly the factors discussed previously, such as appropriate preventative measures and adequate KS, could have contributed to a retained sentiment that the referring physician was still a barrier to care. However, it is worth considering factors beyond the training of the referring physician – factors relating to the patient-physician relationship as it exists in the PRC.

Edmund Pellegrino, an acclaimed American bioethicist, has proposed seven models of a physician's responsibility toward his patients. The social functionary model is one such framework for evaluating the patient-physician relationship wherein physicians practice medicine to serve society as a whole when treating the individual patient.[ 22 ] According to this model, a physician practicing in a resource-limited setting would apportion resources in order to maximize health benefits for the entire population.[ 3 ] In our surveyed population, the referring physicians may have had to weigh the costs of referral and treatment against the potential health benefits that would result for the individual patient. If the physicians believed the costs of referral and further use of medical resources outweighed the benefits, then the physician would be acting appropriately to withhold referral in order to conserve limited resources for a situation where greater health benefits could be derived. Renzong Qiu, a leading Chinese bioethicist, points out that collectivism is fundamental to the ethical framework of Chinese society.[ 6 20 24 25 ] Thus, the tendency for western physicians to treat the patient as a unique entity and remain essentially unaffected by external pressures might be absent in the PRC, where Chinese physicians are more likely to treat patients as integrated elements within the larger society.

Recent studies analyzing the changing face of the patient-physician relationship over the previous several years describe its dissolution as a result of healthcare commercialization within the PRC.[ 13 33 36 ] The transition from a government-funded healthcare system to a commercialized one has forced hospitals to adjust to a more business-focused infrastructure. For the patient, this has translated into increasing medical costs and has resulted in mounting patient distrust towards physicians.[ 33 36 ] The high patient volumes forced upon practicing physicians compound the issue. This has culminated in longer wait times, briefer doctor face-time, and a decreased dialogue between doctor and patient regarding the most appropriate management for each individual.[ 36 ] Overall, these factors could be manifesting in generalized disdain for the referring physician and may be reflected as a perceived barrier to surgical care by the families once they arrived at SCMC and participated in the survey.

There are several limitations to the present study worth noting. First, given the small study size, limited to 69 children in one hospital in the PRC, generalizing these results to the entire PRC may be difficult. Additionally, the barriers to surgical care elicited from our surveyed families represent the insights of those who eventually arrived at a tertiary medical facility to receive treatment. The experiences of families who were unable to receive treatment or received treatment elsewhere may have yielded different perceived barriers had that population been interviewed. To our knowledge, there are no studies to date reviewing the rates of untreated NTDs, making the full spectrum of possible barriers difficult to surmise. Finally, the results of this study are the product of a preformed survey. Thus, while the referring physician was seen as a primary impediment to appropriate surgical care, study participants did not elaborate upon reasons for this perception.

CONCLUSION

The barriers to surgical care for NTDs in the PRC are complex. Further evaluation and eventual mitigation of those barriers requires the perspective of the affected patients and families. The results of this study highlight the referring physician as a primary barrier to care. The younger age at time of treatment for Baobei orphans born with NTDs supports this finding, as they essentially bypassed the referral process. An elaboration on reasons for this real or perceived barrier may provide insight into a means for expedited diagnosis and treatment of NTDs within the PRC.

Financial support and sponsorship

UCLA Center for World Health at the David Geffen School of Medicine.

Conflicts of interest

There are no conflicts of interest.

References

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Abstract

Background:Although intraventricular hemorrhage (IVH) is very rarely reported in full-term neonates, it may occur in children with perinatal trauma, asphyxia, and coagulation disorders, and may originate in the choroid plexus and residual subependymal germinal matrix layer.

Case Description:We present the case of a full-term baby with IVH. She had no perinatal problems or coagulation disorders. Sagittal views of neuroimages demonstrated that the IVH possibly extended from a subdural hemorrhage (SDH) in the infratentorial area via a perforated suprapineal recessus. This was barely visible on a conventional axial view of a computed tomographic scan.

Conclusion:When the etiopathogenesis of IVH in a full-term baby with an uncomplicated delivery cannot be clearly defined, multi-directional and multi-modal neuroimaging may be useful.

Keywords: Full-term birth, infratentorial subdural hemorrhage, intraventricular hemorrhage, suprapineal recessus

INTRODUCTION

Intraventricular hemorrhage (IVH) in the subependymal germinal matrix layer is the most common type of neonatal IVH. It is characteristically observed in premature infants,[ 6 ] and the younger the gestational age, the more often it occurs.[ 10 ] IVH is very rarely reported in full-term neonates. However, it may occur in these children with various clinical conditions, and is mostly related to perinatal trauma, asphyxia, and coagulation disorders.[ 5 9 ] Often, IVH in full-term neonates originates in the choroid plexus and residual subependymal germinal matrix layer.[ 6 10 ]

Here, we report the case of a full-term baby with IVH, which possibly extend from a subdural hemorrhage (SDH) in the infratentorial area via a perforated suprapineal recessus.

CASE REPORT

A full-term (37 weeks and 4 days) baby girl was born in good general condition by vaginal delivery. Her 22-year-old mother (gravida 1, para 1) experienced an unremarkable pregnancy, apart from testing positive for chlamydia antibody at 28 weeks, for which she received azithromycin. The girl's birth weight was 2862 g, length 48 cm, head circumference 33 cm, and Apgar score 9/10. Thirty minutes after her birth, sporadic ventricular premature contractions were frequently observed. She started breastfeeding 8 hours after birth, and she vomited a couple of times. She developed apneic attacks during the night. Subsequently, generalized seizure was observed in the morning of the next day and she was transferred to our hospital.

On arrival, the girl was not very active. There were no trauma-related lesions, including cephalohematoma, on her outer surface. Her seizure was controlled using intravenous administration of phenobarbital. Peripheral blood count and coagulation tests, including prothrombin time and activated partial thromboplastin time, were within normal limits. Ultrasound imaging of her head showed a high echoic lesion in the lateral ventricles. Axial computed tomographic (CT) images revealed IVH in the bilateral lateral ventricles, the 3^rd ventricle and the 4^th ventricle. However, SDH with subarachnoid hemorrhage (SAH) was barely visible compared with the IVH [ Figure 1a ]. Nonetheless, mid-sagittal views clearly demonstrated SDH with SAH in the infratentorial area and the tentorial incisura, which was seen to be connected to the IVH in the 3^rd ventricle via the superior pineal recessus [ Figure 1b ]. The density of the IVH was more intense than that of SDH.

Figure 1

Computed tomographic (CT) scan on day 1 after birth. (a) Axial images revealing intraventricular hemorrhage (IVH) in the lateral ventricles, the 3^rd ventricle, and the 4^th ventricle. Compared with the IVH, the subdural hemorrhage (SDH) in the infratentorial space and tentorial incisura (white arrows), and the hematoma in the suprapineal recessus (white dotted arrow) are barely visible. (b) Mid-sagittal views. The quadrigeminal cistern in the tentorial incisura (white arrows) is seem to be connected to the IVH in the third ventricle via the suprapineal recessus (white dotted arrow)

Because her fontanel was not tense and general conditions were good, conservative therapy for the intracranial hemorrhage was selected. Although protein C activity was slightly decreased (probably due to her intracranial hemorrhage), protein S activity, antithrombin III, and factor XIII were within normal limits.

Around day 13 after birth, the girl's head circumference had gradually increased in size. On day 18, magnetic resonance (MR) images showed marked enlargement of the entire ventricular system [ Figure 2a ]. Although most of the IVH was resolved [ Figure 2a ], the infratentorial SDH persisted [ Figure 2b ]. The 3D heavily T2-weighted imaging (3D-hT2WI) showed internal cerebral veins (ICVs) visualized as a linear signal void at the roof of the 3^rd ventricle and an enlarged suprapineal recessus [ Figure 2c ]. MR venography revealed an intact Galenic venous system, including ICVs. T2*-weighted imaging and MR angiography failed to reveal the causative bleeding point, which included the subependymal layer and the choroid plexus.

Figure 2

Magnetic resonance (MR) images on day 18 after birth. (a) Axial and (b) sagittal views of T1-weighted images show marked enlargement of the ventricular system. The infratentorial SDH persists (white arrows), while most of the IVH is resolved. (c) Sagittal heavily T2-weighted images show an enlarged suprapineal recessus (white dotted arrow), which appears to extend into the infratentorial SDH (white arrows). Internal cerebral veins (ICVs) are depicted as a linear signal void at the roof of the third ventricle and the suprapineal recessus (white arrow heads)

On Day 19, the girl underwent a ventricle-peritoneal (VP) shunt through the right anterior horn. Her postoperative course was uneventful and her development corresponded to her age.

DISCUSSION

In this full-term baby, without coagulation disorders, both massive IVH and infratentorial SDH was observed at first CT scan. Although most of the IVH was resolved, infratentorial SDH persisted at follow-up MRI. However, the causative bleeding spot of the IVH was not noted. These findings might indicate that the SDH was the primary hemorrhagic site and the IVH was an extension of the infratentorial SDH.

The most common etiology of infratentorial SDH is disruption of the tentorium or falx with tearing of the bridging veins due to mechanical compression and distortion of the head during birth.[ 4 11 ] Massive SDH may also occur after dural sinus and rupture of the Galenic venous system. Because infratentorial SDH in term infants is frequently associated with breech delivery, use of forceps, and prolonged labor with cranial melding, infratentorial SDH has been considered to be a traumatic lesion related to difficult parturition.[ 2 3 4 7 11 ] However, recent studies using modern neuroimaging techniques have concluded that the presence of SDH is not necessarily indicative of excessive birth trauma and may occur as the sequela of an otherwise uncomplicated delivery.[ 1 2 3 12 ] Nonetheless, one should be alert to possible underlying causes, including coagulation abnormalities.[ 1 2 ] Because neither difficult parturition nor coagulation abnormalities were observed, the present case could be diagnosed as a “spontaneous” infratentorial SDH. MR venography and 3D-hT2WI did not show any rupture of the Galenic venous system, therefore, the possible causative bleeding spot was injury of the bridging cerebellar veins.

Spontaneous SDH located in the infratentorial region is difficult to see on axial CT scans, since the axial plane is not completely parallel to the tentorium, and it can therefore be overlooked.[ 12 ] In our case, from the axial view, the infratentorial SDH was barely visible, while the massive IVH was clearly visible. However, mid-sagittal views clearly demonstrated that the infratentorial SDH could be connected to the IVH in the 3^rd ventricle via the superior pineal recessus [ Figure 1b ]. The suprapineal recessus projects posteriorly between the upper surface of the pineal gland and the lower layer of the tela choroidea in the roof of the 3^rd ventricle.[ 8 ] The ependymal tissue of the suprapineal recessus is thought to be thin in neonates. Thus, it is reasonable that the extension and pressure of the infratentorial SDH may have directly perforated the ependyma of the suprapineal recessus [ Figure 3 ]. If the bleeding spot was adjacent to the suprapineal recessus, it could be speculated that the direct pressure of the SDH would be large enough to perforate the suprapineal recess, with a large hematoma extending into the ventricles. This is a possible reason why the density of the IVH was greater than that of the SDH at the initial CT scan. While our hypothesis was not proved and the possibility of the simultaneous occurrence of IVH and SDH cannot be completely excluded, when the etiopathogenesis of IVH cannot be defined clearly on conventional axial CT scans, multi-directional and multi-modal neuroimaging may be recommended.[ 10 ]

Figure 3

A schematic drawing of our hypothesis concerning the IVH development in this case. Infratentorial SDH, which occurred owing to injury of bridging veins (indicated with x) from the straight sinus (SS) near the suprapineal recessus. The ependyma of the suprapineal recessus was perforated below the entry of ICVs (bold black arrow) and thus IVH (indicated with bold black arrow) developed in the 3^rd ventricle (III), the bilateral lateral ventricle (LV), and the 4^th ventricle (IV)

The outcome of the infratentorial SDH depends on the parenchymal and brainstem involvement.[ 4 7 ] When the infratentorial SDH is massive, the large hematoma extends to the cerebellar parenchyma, compressing the 4^th ventricle and the brainstem.[ 4 7 ] In the present case, no parenchymal or brainstem involvement were observed because the infratentorial SDH probably drained into the ventricles through a perforated suprapineal recessus. Because a VP shunt successfully controlled the patient's post-IVH communicating hydrocephalus, her prognosis is expected to be good.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Ahmad K, Zafar Janjua N, Bin Hamza H, Imran Khan M. Spontaneous subdural haemorrhage in new born babies. Lancet. 2004. 363: 2001-2

2. Brouwer AJ, Groenendaal F, Koopman C, Nievelstein R-JA, Han SK, de Vries LS. Intracranila hemorrhage in full-term newborns: A hospital-based cohort study. Neuroradiology. 2010. 52: 567-76

3. Chamnanvanakij S, Rollins N, Perlman JM. Subdural hematoma in term infants. Pediat Neurol. 2002. 26: 301-4

4. Hayashi T, Hashimoto T, Fukuda S, Ohshima Y, Moritaka K. Neonatal subdural hematoma secondary to birth injury. Clinical analysis of 48 survivors. Childs Nerv Syst. 1987. 3: 23-9

5. Ichiyama M, Ohga S, Ochiai M, Fukushima K, Ichimura M, Torio N. Fetal hydrocephalus and neonatal stroke as the first presentation of protein C deficiency. Brain Dev. 2016. 38: 253-6

6. Morioka T, Hashiguchi K, Nagata S, Miyagi Y, Mihara F, Hikino S. Fetal germinal matrix and intraventrucular hemorrhage. Pediatr Neurosurg. 2006. 42: 354-61

7. Perrin RG, Rutka JT, Drake JM, Maltzer H, Hellman J, Jay V. Management and outcome of posterior fossa subdural hematomas in neonates. Neurosurgery. 1997. 40: 1190-200

8. Rhoton AL J.editors. The lateral and third ventricles. RHOTON Cranial anatomy and surgical approaches. Maryland: Lippincott Williams & Wilkins; 2003. p. 235-99

9. Sahriarian S, Akbari P, Amini E, Dalili H, Esmaeilnia Shrivany T, Niknafs N. Intraventricular hemorrhage in a term neonate: Manifestation of protein S deficiency. A case report. Iran J Public Health. 2016. 45: 531-4

10. Szpecht D, Frydryszak D, Miszezyk N, Szymankiewicz M, Gadzinowski J. The incidence of severe intraventricular hemorrhage based on retrospective analysis of 35939 full-term newborns. Report of two cases and review of literature. Childs Nerv Syst. 2016. 32: 2447-51

11. Usul H, Karaarslan G, Cakir E, Kuzeyl K, Mungan I, Baykal S. Conservative management of spontaneous posterior fossa subdural hematoma in a neonate. J Clin Neurosci. 2004. 12: 196-8

12. Whitby EH, Griffiths PD, Rutter S, Smith MF, Springg A, Ohadike P. Frequency and natural history of subdural haemorrhages in babies and relation to obstetric factors. Lancet. 2003. 362: 846-50

Abstract

Background:Aplasia cutis congenita (ACC) is a part of a heterogeneous group of conditions characterized by the congenital absence of epidermis, dermis, and in some cases, subcutaneous tissues or bone usually involving the scalp vertex. There is an estimated incidence of 3 in 10,000 births resulting in a total number of 500 reported cases to date. The lesions may occur on every body surface although localized scalp lesions form the most frequent pattern (70%). Complete aplasia involving bone defects occurs in approximately 20% of cases. ACC can occur as an isolated defect or can be associated with a number of other congenital anomalies such as limb anomalies or embryologic malformations. In patients with large scalp and skull defects, there is increased risk of infection and bleeding along with increased mortality and therefore prompt and effective management is advised.

Case Description:We describe two cases of ACC, involving a 4 × 3 cm defect managed conservatively and a larger 10 × 5 cm defect managed surgically with the use of a temporo-occipital scalp flap. Both cases had an excellent outcome.

Conclusions:Multiple treatment regimens exist for ACC, but there is no consensus on treatment strategies. Conservative treatment has been described and advocated, but many authors have emphasized the disadvantages of this treatment modality. Decision between conservative and surgical management must be individualized according to lesion size and location.

Keywords: Aplasia cutis congenita, congenital anomalies, cranial reconstruction, scalp reconstruction

INTRODUCTION

Aplasia cutis congenita (ACC) is a heterogenous group of disorders reported historically by Cordon in 1767, and characterized by the absence of epidermis, dermis, and occasionally subcutaneous tissues or even bone tissue, involving multiple possible body locations. The most common lesion location is the scalp (70%);[ 17 41 43 ] however, any skin site can be affected and there is also a rare universally fatal subcategory affecting the majority of the dermis.[ 51 59 ] In 1986, a classification system was devised by Frieden consisting of nine main ACC types based on the number, the location of the lesions, and the presence or absence of associated deformities,[ 13 ] which is shown in Table 1 .[ 7 ]

Table 1

Frieden classification of ACC types

ACC holds an estimated incidence of about 3 in 10,000 births and there has been a total of approximately 500 reported cases in the literature.[ 32 ] The strongest risk factor reported in the literature is the antithyroid drug Methimazole,[ 18 20 21 39 40 55 ] which according to Frieden classification, can be categorized into type 8 ACC. However, cases of ACC are extremely limited due to the very low incidence and, therefore, it is not possible to derive completely accurate epidemiological data.

Pathophysiology of ACC is not well studied and its exact pathogenesis is unknown.[ 11 22 30 35 36 ] However, there are multiple factors that are probably contributing to the development of ACC according to the literature:

Chromosomal abnormalities,[ 8 31 ] especially BMS1[ 29 ]; a recent study has also implicated the UBA2 gene and the SUMOylation pathway[ 27 ]

The main pathophysiologic hypothesis about ACC is that the mechanism behind it lies in tension-induced disruption of the overlying skin occurring at 10–15 weeks of gestation when rapid brain growth occurs along with hair direction and patterning.[ 31 ] Another less prevalent model is that premature amniotic membrane rupture and amniotic band formation might be the cause of ACC.[ 7 ]

CASE DESCRIPTIONS

The following cases are categorized as group 1 ACC and involve patients with multiple scalp bullous lesions, with both skin and bone layer defects. We will describe both cases and discuss presentation, prognosis, and management strategies.

First case

Our first patient was a 3300 g white boy of 37 weeks of gestation. Pregnancy, labor, and delivery were without any mishaps. From the obstetrical record, we were informed that the mother was treated for hypothyroidism with T4 and also with Ritodrine (Utopar®) due to uterine contractions. No abnormal family history was reported. At birth, the boy was found to have three sizable bullae on his scalp. There was a large round-shaped occipital defect at the vertex with dimensions of 4 × 3 cm and two lesser ones at the frontal vertex with dimensions of 1 × 2 and 1 × 1 cm [Figures 1 and 2 ]. The defects included both scalp and skin layers and were confirmed by ultrasound and computed tomography (CT) scan examinations. The CT scan also revealed suture diastasis with thinning and hypoplasia of the fronto-parietal bones [ Figure 3 ]. A thin membrane was covering the defect in immediate proximity to the superior sagittal sinus. During the following days, a dark dry eschar developed covering the lesion. A conservative management strategy was adapted due to relatively small size of the lesions. The wound was vigorously cleaned daily initially with betadine solution and furthermore with fucidin gauze and sterile dressings. The eschar became well demarcated shortly and the healing process was mostly satisfying. Intravenous chemoprophylaxis with third-generation Cephalosporin (Cefotaxime®) and Teicoplanin (Targocid®) was concomitantly administered. Complete wound closure occurred at 42 days.

Figure 1

The largest (4×3) bullous defect of the first case

Figure 2

All 3 scalp bullous defects of the first case

Figure 3

The CT scan, confirmed the defects which involved both bone and skin layers, and revealed suture diastasis with thinning and hypoplasia of fronto-parietal bones

Second case

Our second patient was a 3660 g white boy of 42 weeks of gestation. Pregnancy, labor, and delivery were without any mishaps. The obstetrical record included history of induced delivery. The medical record revealed a family history of ACC involving the patient's father and siblings. At birth, the patient had an extensive round-shaped hemorrhagic bullae with dimensions of 10 × 5 cm above the fronto-occipital regions of the scalp [Figures 4 and 5 ]. The defect included scalp and skin layers, which was confirmed by ultrasound and magnetic resonance imaging (MRI) scan examinations [ Figure 6 ]. The MRI scan revealed a complete loss of continuity of the dermal and subcutaneous tissues [ Figure 6 ]. Yet again, a thin membrane covered the defect in immediate proximity to the superior sagittal sinus. In contrast to the first case, in this case surgical treatment was adapted due to the increased size of the lesion, along with the proximity to the superior sagittal sinus. The defect was covered by using a single temporo-occipital scalp flap. Chemoprophylaxis was given with intravenous injections of Ceftazidime (Solvetan®) and Teicoplanin (Targocid®). During the postoperative period, blood examinations showed increased inflammatory indexes and blood cultures were found positive for Enterobacter cloacae, and therefore antibiotic treatment was modified to Meropenem (Meronem®) and Vancomycin (Voncon®). Unfortunately, the infant developed septic shock influencing coagulation factors VII and IX, and thus was promptly provided with units of fresh frozen plasma. Defected areas were treated with betadine scrub and sterile gauze dressing. Following daily local treatment, the wound gradually epithelialized, and complete epithelialization was achieved at 37 days.

Figure 4

Our second case had an extensive defect (10×5) above the fronto-occipital regions of the scalp

Figure 5

A thin membrane was covering the defect in immediate proximity to the superior sagittal sinus

Figure 6

MRI confirmed that the defect included scalp and skin layers and revealed complete loss of continuity of the dermal and subcutaneous tissues

DISCUSSION

In the majority of cases (70%) ACC manifests as a solitary defect of the scalp, but occasionally it may present with multiple lesions such as in our first case. Although lesions are noninflammatory and well demarcated, there is great controversy concerning treatment of ACC and there has been a great scientific interest due to the extremely high mortality figures that range from 20 to 55%.[ 38 ] High mortality/morbidity rates are a result of sagittal sinus bleeding, secondary local infection, meningitis, sagittal sinus thrombosis, or the direct result of other serious congenital defects that are associated with ACC.[ 19 26 38 ] On examining both the presented cases, it was observed that both had lesions in very close proximity to the superior sagittal sinus; therefore, the imminent risk of infection and bleeding is apparent. Bleeding of the superior sagittal sinus is the most life-threatening complication of ACC with 36% mortality.[ 19 ] This fatal complication occurs between 1 and 3 months of age, has been shown to be more frequent with lesions involving a larger portion of the superior sagittal sinus, and is probably the cause of superior sagittal sinus exposure and insufficient protection.[ 19 ] It is important to prevent such fatal complications through prompt and effective ACC management.

The management of scalp ACC is controversial. Treatment may be either conservative or operative, and there is no consensus or guidelines on treatment strategy. Choosing between conservative and operative modalities is challenging and should be individualized.[ 47 ] Lesion size is the only universally accepted criterion with larger lesions favoring the surgical approach.[ 6 ] Additionally, lesion location plays an important role, with lesions above critical areas, especially with sagittal sinus compromise favoring a surgical approach due to increased bleeding and infection risk.[ 50 ]

Conservative management consists of regular wound cleansing and application of dressings along with the use of systemic antibiotics.[ 18 ] This includes physiological saline, continuous saline drips, betadine solution, bacitracin ointment, and silver sulfadiazine dressings,[ 37 ] which are utilized in order to preserve moisture, prevent desiccation, and allow spontaneous epithelialization to occur.[ 48 56 58 ] There are multiple reports of specialized adherent wound dressings that are thought to offer increased wound healing rates,[ 3 4 23 ] as well as recent reports of novel dressing materials such as fatty gauzes.[ 49 ] However, none of the more specialized dressing materials have proven to be significantly superior, and therefore, it is accepted to treat ACC with standard traditional wound care.[ 30 ] Although conservative treatment has traditionally been the default strategy for normal and small-sized lesions, lately there have been reports of extensive ACC lesions managed through the conservative route with excellent healing results,[ 14 37 ] and this shows a tendency of recent literature in favor of the conservative approach. In addition, there have been reports of even more specialized conservative treatment techniques such as the use of autologous cultured fibroblasts and keratinocytes[ 10 ] or the application of fibroblast growth factors that accelerate wound healing, a modality which might represent the future of ACC treatment drastically decreasing the number of surgically managed cases.[ 33 ]

Surgical management, on the contrary, includes various procedures. Standard surgical care includes primary wound closure, skin grafting (autologous or allografts),[ 5 26 57 ] local scalp flaps with or without tissue expansion,[ 37 54 ] free flaps,[ 26 ] muscle flaps,[ 52 ] full-thickness or split-thickness skin grafts,[ 1 45 ] and cranial vault reconstruction using bone grafts.[ 16 37 ] Specialized surgical techniques such as utilizing bipedicle opposing local flaps,[ 12 32 ] rotational flaps,[ 24 31 42 50 ] or L-shaped flaps[ 2 ] have been used with satisfying results. However, wound repair through a single, large scalp flap seems adequate and effective for the majority of ACC lesions,[ 38 ] offering adequate wound closure and protection of the sensitive underlying structures. Closure of the associated skull defect is usually achieved through the use of artificial bone grafts, which should be designed according to current bone defect size, although the use of autologous bone grafts has been described.[ 16 34 ] Bone defects, according to the literature, can self-regenerate with an impressive speed,[ 57 ] however, many authors advise to repair skin defects and skull defects concomitantly for optimal results,[ 34 ] or in a delayed cranioplasty operation. In conclusion, the exact surgical technique must be tailored according to each individual patient and lesion, as well as the surgeons personal preference and expertise.[ 6 ] Surgery for ACC is accompanied by the usual complications of every surgical operation, and consists mainly of intraoperative hemorrhage and postoperative infections. These complications are rare, but can be effectively managed. Since ACC mortality is particularly high especially for larger lesions due to similar complications involving both life-threatening hemorrhage and infection, postoperative complications should not be considered as a discouraging factor when managing a patient with an extended ACC lesion.[ 31 ]

CONCLUSION

In conclusion, we strongly believe that a conservative approach minimizes complications, avoids unwanted operative sequelae, and takes full advantage of the innate rapid regeneration ability of the newborn.[ 17 ] Therefore, whenever the conservative approach seems feasible, it is strongly advised to initially adapt it and save the surgical approach in cases of treatment failure.[ 41 ] In the near future, even more technologies are about to emerge to facilitate wound healing and wound closure, such as fibroblast growth factors and cultured skin, possibly even rendering surgical management obsolete. Throughout the literature, there are reports of extremely large defects treated conservatively with impressive results,[ 14 ] however, there are no reports of surgical management for lesions of size <30 cm².[ 25 ] Present publications generally illustrate that conservative management is preferable, and surgical management is generally considered, but not always utilized, for lesions of size >30 cm².

In our specific cases, we utilized a conservative approach in Case 1, which involved a smaller defect (1 × 2 cm), whereas for the larger defect of Case 2 (10 × 5 cm), a surgical approach with the application of a single scalp flap was utilized. Results were satisfying in both cases, with complete wound closure. Taking into account both our own experience and the literature, we strongly believe that utilizing a size threshold for deciding between conservative or surgical approach along with meticulous sterile dressings and wound care is the optimal management strategy for ACC. The optimal size threshold and specific treatment guidelines remain yet to be determined. The literature complete lacks any precise guidelines or suggestions on the subject and further research is required. Therefore, it must be noted that due to the lack of treatment algorithms and guidelines on ACC management and the need for individualized treatment decisions, it is important for such cases to be managed in centers specialized in pediatric neurosurgery with sufficient experience and expertise.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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Abstract

Background:Intracranial arachnoid cysts are space-occupying lesions that typically remain stable or decrease in size over time. Cysts in infants younger than 1 year of age are remarkably different from those in older children and adults in terms of cyst localization and enlargement. Arachnoid cysts of the posterior fossa (PFACs) are very rare in infants and do not typically grow or present with clinical symptoms, such that surgical treatment is generally considered to be unnecessary. Here, we describe an extremely rare case of an infant with a rapidly enlarging symptomatic PFAC that was successfully treated with surgery.

Case Description:A 4-month-old boy presented with increasing head circumference and a rapidly enlarging arachnoid cyst in the left posterior fossa with ventriculomegaly, which was documented using serial imaging over the preceding 2 months. We performed a microscopic resection of the cyst membrane to remove the mass effect as soon as possible and facilitate normal development. To confirm dural closure and prevent cerebrospinal fluid leakage, we also performed short-term (7 days) percutaneous long-tunneled external ventricle drainage after the surgery. Magnetic resonance imaging over a 4-year follow-up period revealed adequate reduction of the ventricle and cyst. The patient no longer exhibited progressive macrocrania and showed normal development.

Conclusion:To our knowledge, this is the second successful case of surgical treatment of an enlarging symptomatic PFAC in an infant. Our surgical strategy for the treatment of this rare case can serve as a guide for surgeons in similar future cases.

Keywords: Arachnoid cyst, cyst enlargement, hydrocephalus, posterior fossa

INTRODUCTION

Congenital arachnoid cysts are rare central nervous system malformations that represent only 1–2% of all intracranial masses.[ 23 ] These lesions are often clinically silent and rarely increase in size.[ 1 12 13 19 ] As such, arachnoid cysts seldom require surgical intervention.

The characteristics of arachnoid cysts vary remarkably between infants and older children or adults. In adults, the majority of intracranial arachnoid cysts arise in the supratentorial region (90%), with the middle cranial fossa being the most common site (60%) of origin and 10–20% of arachnoid cysts occurring in the posterior fossa.[ 4 7 22 ] In contrast, arachnoid cysts in infant patients commonly occur at the middle fossa (15%) and intraventicularly (14%), with very low percentages occurring in the posterior fossae (4.6%).[ 13 ] Lee et al. recently reported that cysts in infants can occasionally enlarge (16.2%), but that arachnoid cysts of the posterior fossa (PFACs) have an extremely low prevalence of enlargement in infant cases (2.3%)[ 13 ] and are generally asymptomatic such that they do not require treatment.

Here, we present an extremely rare case of a 4-month-old boy who presented with a rapidly enlarging symptomatic PFAC. After considering the current options for treating symptomatic PFACs in infants,[ 1 3 11 14 18 22 24 ] we performed a necessary microscopic membranectomy with post-surgical percutaneous long-tunneled external ventricle drainage (PL-EVD)[ 5 15 ] and obtained a good outcome. Because this is the second successful case of surgical treatment for an enlarging symptomatic PFAC in an infant,[ 3 ] the surgical strategy described here can guide surgeons in future clinical decisions.

CASE PRESENTATION

History

The patient in the present case was a boy that was born by vaginal delivery at 42 weeks of gestation. He had a birth weight of 2546 g, a normal head circumference (32.1 cm), and exhibited no neurological abnormalities. Based on the detection of an ultrasonographic abnormality, magnetic resonance imaging (MRI) was performed at 58 days after birth and a cystic lesion (1.2 cm × 2.9 cm at its largest diameter) was identified in the left retrocerebellar region of the posterior fossa [ Figure 1 ]. The cerebellum was smaller than average, but there were no signs of significant compression. At this time, the circumference of the patient's head was slightly enlarged and measured in the upper limit for his age group (43.0 cm).

Figure 1

Initial sagittal (a) and axial (b) T2 magnetic resonance images of the male patient at 58 days of age. The image demonstrates a cystic lesion with the septum (arrow) in the posterior fossa

Examinations

At 4 months of age, the patient's head circumference increased to 48.0 cm (>2 standard deviations above the mean for his age), and MRI showed significant enlargement of the cyst (4.0 cm × 3.5 cm at its largest diameter) with compression of the cerebellum and hydrocephalus caused by obstruction of the fourth ventricle outlets [ Figure 2 ]. Intracranial hypertension was also recognized based on sunset phenomena in the patient's eyes, scalp varicosis, and separation of the coronal and sagittal cranial sutures. The patient did not exhibit any other abnormal neurological signs, and was diagnosed with an enlarging PFAC and obstructive hydrocephalus.

Figure 2

Preoperative sagittal (a) and axial (b) T2 magnetic resonance images of the patient at 4 months of age. An enlarged cystic lesion can be observed descending into the foramen magnum with the septum expanding beyond the midline (arrow). Blocked communication with the fourth ventricle, compression of the brainstem and fourth ventricle (arrowheads), and marked ventriculomegaly (stars) were evident

Surgical procedure

Clinical signs and symptoms of hydrocephalus were observed when the patient was 4 months of age. Thus, we performed a suboccipital craniotomy and direct microscopic treatments to resect the cyst membrane via a medial occipital approach with the patient in the prone position. This was done to restore normal communication between the Magendie and Lushka foramina and the subarachnoid space. Because the inner membrane of the cyst adhered to the rostral medullary velum and compressed the fourth ventricle, we carefully detached and resected both the outer and inner membranes of the cyst to open the fourth ventricle and cisterna magna [ Figure 3 ]. During the surgery, we confirmed good cerebrospinal fluid (CSF) flow at the cerebral aqueduct and cisterna magna. A histopathological study of excised tissues stained with hematoxylin and eosin showed arachnoid mesothelial cells arranged among fibers of the connective tissue (data not shown), confirming our diagnosis. Immediately prior to the craniotomy, we performed PL-EVD to allow for external CSF drainage for 7 days after the surgery to prevent infection due to CSF leakage.[ 5 ] The procedure of PL-EVD was as follows. The posterior horn of the lateral ventricle was cannulated with a ventricular catheter. The peritoneal catheter was then subcutaneously tunneled with the proximal end connected to the distal end exiting at the lower anterior chest wall, 25 cm away from the proximal end. The distal catheter was then secured to the skin and connected to a ventricular drainage system.

Figure 3

Intraoperative photographs. (a and b) The cyst wall was exposed and resected. (c) Opening of the cerebral aqueduct was confirmed. (d) Opening of the foramen magnum was confirmed

Postoperative course

The postoperative course was uneventful. MRI performed 1 month after the surgery revealed that the cyst had disappeared, alleviating compression of the cerebellum and halting the patient's macrocrania. Further, the sulci of the cerebellum and the cerebellar pontine angle became easier to observe. At the last follow-up (performed 4 years postoperatively), the cyst wall was unidentifiable and the cerebellum had grown to near-normal size [ Figure 4 ]. The patient was doing well and showed normal development.

Figure 4

Computed tomography performed 4 years after the surgery. The image demonstrates absence of the septum as well as reduced compression of the brainstem and fourth ventricle. Furthermore, the image clearly depicts the sulci of the cerebellum, the cerebellopontine angle, and amelioration of the patient's obstructive hydrocephalus

DISCUSSION

An arachnoid cyst consists of a cavity lined with arachnoid cells and filled with fluid that closely resembles CSF.[ 23 ] Most arachnoid cysts are clinically silent and remain static in size; however, on rare occasions, these cysts can increase in size and produce symptoms due to mass effects.[ 1 12 13 19 ] Although the mechanisms that drive arachnoid cyst enlargement remain unknown, it has been postulated that cysts may expand due to (1) a ball-valve action that allows CSF entry into the cyst; (2) intracystic production of fluid by secreting cells occasionally found on the cyst walls; or (3) movement of fluids following an osmotic gradient.[ 10 23 ]

The differential diagnosis of PFACs in infants mainly includes the Dandy–Walker malformation, mega cisterna magna, and Blake's pouch cyst.[ 6 23 ] It is also important to exclude other possible cystic lesions such as cerebellar cystic astrocytoma, cystic hemanglioblastoma, and epidermoid or dermoid tumors.[ 6 ] MRI findings are very useful for the differential diagnosis of a PFAC, as demonstrated in our present case. Finally, postoperative histological studies are also useful for a definitive diagnosis.

Although very little data exist regarding the clinical characteristics of arachnoid cysts in infant cases, these characteristics have gradually become evident.[ 3 11 13 18 20 ] Lee et al. demonstrated differences in cyst localization between infants younger than 1 year of age and older children and adults, additionally indicating a much lower prevalence of PFACs in infants compared to adults.[ 13 ] Further, the authors found that even enlarging PFACs in infants did not necessarily warrant surgical treatment based on the absence of clinical symptoms. Accordingly, the present case of a 4-month-old boy with a rapidly enlarging symptomatic PFAC and successful surgical treatment is extremely rare and thus of clinical value.

To date, only 2 cases of enlarging symptomatic PFACs and surgical treatment have been reported in infant patients [ Table 1 ].[ 3 ] Both patients in these cases were younger than 9 months of age and were treated by endoscopic fenestration, but clinical improvement was reported in only 1 case. Thus, our present case is the second report of successful surgical treatment of a rapidly enlarging symptomatic PFAC in an infant.[ 3 ]

Table 1

Reported infant cases of enlarging symptomatic arachnoid cysts of the posterior fossa with surgical treatment

The infratentorial space is much smaller than the supratentorial space; accordingly, mass effects related to arachnoid cysts are more probable in the infratentorial space than in the supratentorial space. Especially in infants with very small infratentorial spaces, mass effects must be removed as soon as possible to facilitate normal development.

PFACs can be particularly challenging to treat depending on the cyst size, cyst location, and the presence of obstructive hydrocephalus.[ 6 21 ] To this end, there is no consensus regarding a standard or optimal surgical treatment for PFAC. Various treatment approaches exist, including microsurgical excision or fenestration by craniotomy, cyst shunting, and endoscopic fenestration.[ 1 3 11 14 18 22 24 ] While some authors have reported that there is no significant difference between these surgical methods,[ 2 8 ] studies evaluating the management of PFACs in a pediatric population demonstrated that craniotomy with excision was the first-line approach.[ 14 16 ] We selected to perform a microscopic membranectomy of both the inner and outer membranes because the resolution of obstructive hydrocephalus was a high priority and it was necessary to remove the mass effect to facilitate normal development of the infant.

There is relatively high risk of postoperative complications such as CSF leakage, subdural fluid collection, and meningitis after surgery on the posterior fossa, especially in infants.[ 3 9 17 18 ] In the present case, we performed PL-EVD and continued drainage for 7 days after surgery to confirm dural closure and prevent CSF leakage, which may have led to an infection such as meningitis.[ 5 15 ] After removal of the drainage tube, no CSF leakage or meningitis was observed and the skin wound healed completely. The reasons for performing PL-EVD are as follows: (1) it is very difficult to stitch and effectively close an incision of the dura mater in the posterior fossa region in infants; (2) as the skin, subcutaneous fat, and muscles of infants are relatively thin, CSF tends to leak externally when the dura mater is breached; (3) it is difficult to evaluate whether infant patients have sufficient ability to reabsorb leaked CSF; and (4) PL-EVD is a simple and effective method for lowering the risk of infection after surgical treatment of a PFAC.[ 15 ] To our knowledge, this is the first case in which PL-EVD performed in an infant with a PFAC. Another necessary precaution during surgical intervention for a PFAC is the protection of important neurovascular structures such as the brainstem. In summary, these surgical considerations and techniques provide important and useful insight for neurosurgeons planning surgical treatment for PFACs in infant patients.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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15. Matsumoto J, Kochi M, Morioka M, Nakamura H, Makino K, Hamada J. A long-term ventricular drainage for patients with germ cell tumors or medulloblastoma. Surg Neurol. 2006. 65: 74-80

16. Oberbauer RW, Haase J, Pucher R. Arachnoid cysts in children: A European co-operative study. Childs Nerv Syst. 1992. 8: 281-6

17. Parizek J, Mericka P, Nemecek S, Nemeckova J, Spacek J, Suba P. Posterior cranial fossa surgery in 454 children. Comparison of results obtained in pre-CT and CT era and after various types of management of dura mater. Childs Nerv Syst. 1998. 14: 426-38

18. Raju S, Sharma RS, Moningi S, Momin J. Neuroendoscopy for Intracranial Arachnoid Cysts in Infants: Therapeutic Considerations. J Neurol Surg. 2015. 77: 333-43

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Abstract

Background:Surgical methods to treat craniosynostosis have evolved from a simple strip craniectomy to a diverse spectrum of partial or complete cranial vault remodeling with excellent results but often with high comorbidity. Therefore, minimal invasive craniosynostosis surgery has been explored in the last few decades. The main goal of minimal invasive craniosynostosis surgery is to reduce the morbidity and invasiveness of classical surgical procedures, with equal long-term results, both functional as well as cosmetic.

Methods:To reach these goals, we adopted endoscopy-assisted craniosynostosis surgery (EACS) supplemented with helmet molding therapy in 2005.

Results:We present in detail our surgical technique used for scaphocephaly, trigonocephaly, plagiocephaly, complex multisutural, and syndromic cases of craniosynostosis.

Conclusions:We conclude that EACS with helmet therapy is a safe and suitable treatment option for any type of craniosynostosis, if performed at an early age, preferably around 3 months of age.

Keywords: Craniosynostosis, endoscopy, helmet, minimal invasive, surgical technique

INTRODUCTION

The history of the identification of different types of craniosynostosis, the underlying pathogenesis, and the subsequent development of surgical treatments for this entity reads as a very entertaining novel. In the last decade, many reports have reviewed the history, treating paradigms, and evolving surgical techniques in much detail.[ 3 26 30 32 34 ] In general, surgical techniques have always reflected the contemporary beliefs about pathogenetic paradigms and have always been limited by the available (or missing) technology, regarding both surgical tools and anesthesia.

At the time Virchow stated his law, it was believed that the observed deformities in craniosynostotic skulls were a result of cessation of growth across a prematurely fused suture, with compensatory growth along nonfused sutures in a direction parallel to the affected suture, causing obstruction of normal brain growth.[ 40 ] Hence, the first surgical attempts to treat this condition in the late 1800s consisted of suturectomy,[ 23 24 ] although it appears that many children treated at that time were more likely to have microcephaly rather than craniosynostosis. This distinction was not diagnosed or considered at that time. As patients were only treated when neurological deficits developed, these procedures were performed at an older age and frequently reossification occurred before correction of the skull shape was established. The outcome of these early procedures was not satisfying and a high mortality rate was associated with these procedures, leading to fierce resistance by Jacobi and discontinuation of this technique.[ 13 ] Some decades later, Faber and Towne reported excellent preservation of neurological function with minimal morbidity and mortality by performing suturectomy for craniosynostosis, presumably well differentiated from microcephaly.[ 8 ] By the 1940s, strip craniectomies were widely accepted and it became clear that early intervention – at that time described as the period before 2 months of age – led to better functional as well as cosmetic outcome, a parameter that was not of primary importance at that time.[ 9 ] However, the problem of reossification in older children remained and required extensive and difficult secondary cranial reconstruction operations, associated with high morbidity and mortality rates. Therefore, several techniques were developed to fight this reossification process, including wrapping of the cut bone edges with polyethylene or tantalium foil or applying Zenker's solution to the dura.[ 1 12 37 ] Wrapping the bone edges led to infections and still early reossification, Zenker's solution caused seizures, hence these techniques were discarded.

By the mid-1950s, there was a significant advance in anesthesia and blood transfusion and surgery for craniosynostosis became very safe. At that time, Moss rejected the Virchow's law and proposed his “functional matrix theory,” stating that the active growth of the underlying brain dictated the passive cranial growth along the suture lines. He proposed that the cranial base and not the suture was the primary site of abnormality, with suture fusion being a secondary consequence.[ 28 ] These beliefs, together with the technological advancement and clear failure of simple strip craniectomy procedures in older patients, led to the development of more extended procedures, in which for the first time cosmesis was considered as a primary indication for surgery by Shillito and Matson.[ 36 ] From the early 1960s to mid-1990s several extensive calvarial remodeling techniques were developed.[ 10 14 38 ] Tessier introduced pioneering techniques for the treatment of craniosynostosis that led to significant improvements in cosmetic outcomes, particularly for those with facial abnormalities.[ 38 ] The limitations of suturectomy for advanced disease and the discovery by Delashaw et al. that a major cause of the cranial deformity was compensatory overgrowth at adjacent sutures, led to techniques in which the desired changes in the shape and volume were established intraoperatively and the bony segments were fixed to maintain the correction.[ 5 ] The outcomes of these techniques do not depend on postoperative brain expansion and are therefore more predictable than simple or extended craniectomy procedures. Therefore, cranial remodeling became the preferred surgical technique for craniosynostosis, although these techniques were associated with significant operative time, hospital stay, ICU monitoring, blood loss requiring transfusion, and complications.[ 36 ] These limitations, especially blood loss and transfusion, were the motor for the development of minimal invasive craniosynostosis surgery techniques, using endoscopes or springs.[ 19 25 ] In the early 1990s, Jimenez and Barone presented their minimal invasive suturectomy via endoscopic approach, supplemented with orthotic helmet molding therapy to treat scaphocephaly.[ 19 ] As their experience grew, subsequent reports noted significant reduction in blood loss and need for transfusions, shorter operative times and hospital stays, decreased hospital costs with good to excellent cosmetic results, not only for scaphocephaly but also for trigonocephaly, anterior plagiocephaly, brachycephaly, and multisutural craniosynostosis.[ 16 17 18 19 20 21 22 23 ] Several other groups have adapted these techniques and confirmed their findings.[ 3 4 6 30 31 35 ]

The main goal of minimal invasive craniosynostosis surgery is to reduce the morbidity and invasiveness of classical surgical procedures, with equal long-term results, both functional and cosmetic.[ 6 29 32 ]

Reducing the morbidity and invasiveness can be achieved by minimizing skin incisions and tissue dissection using the smallest working space possible while keeping good visual control over the surgical field to prevent major blood loss and other complications such as dural tears.

To reach these goals, we introduced endoscopy-assisted suturectomy (ECAS) supplemented with helmet molding therapy in our centre in 2005 and gained extensive experience with this technique.[ 6 ]

METHODS

Surgical technique

General principles and equipment

This type of surgery can be performed with a standard armamentarium including the use of an endoscope with footplate and can be considered as a simple and easy surgery when performed correctly.

To minimize blood loss, we infiltrate the skin with lidocaïne 2% or epinephrine 1:100.000. After skin incisions are made, we use monopolar cutting for galea and periosteum. The craniectomy is then initiated with a high-speed drill and continued with different rongeurs and Kerrisons. Any bleeding during surgery from the epidural space and bone edges is easily controlled with FloSeal® Matrix Hemostatic Sealant and Ostene® bone wax (Baxter Healthcare Corporation, Fremont, CA, USA).

Once a small entrance craniectomy is performed, we use a 0-degree Storz lens scope with a working shaft used for endoscopic facial lift surgery without irrigation or suction to perform dura dissection from the overlying bone and synostotic suture [ Figure 1 ]. This is usually very easy as the dura mater is hardly attached to a synostotic suture, but can be tricky in case of a deep and sharp bony ridge as is often the case in trigonocephaly. Blood aspiration is performed by a separate aspirator placed parallel to the endoscope. The endoscope with footplate allows good visual control of the operative field under the bone, identification and bipolar coagulation of transgressing emissary veins before rupture, and protection of the dura mater during bone resection. Craniectomy is then continued along the length of the affected suture under direct visual control of the endoscope. No subdural/subcutaneous drains are used and a small compressive head bandage is used for 24 h to prevent subcutaneous hematoma development.

Figure 1

Instruments commonly used in EAC surgery. A: bone cutting scissors, B:small suction device, C:bended spatula for dura dissection, D: 0 degree endoscope with footplate

Standard anesthetic monitoring techniques including electrocardiography, noninvasive blood pressure monitoring, pulse oximetry, temperature monitoring, and blood loss monitoring are used. As blood loss and operative times are very limited (30–60 min), there is no need for a central venous line nor an arterial line. Two peripheral venous lines suffice in all cases. Antibiotic profylaxis consists of 25 mg/kg cefazolin i.v. given 20 min before skin incision. Postoperative monitoring is performed in pediatric medium care unit, with hemoglobin/hematocrit levels controlled 6 h after surgery and before dismissal the next day. Postoperative pain is treated with prophylactic paracetamol and low-dose i.v. morphine which can be tapered during the night after surgery. Because of the low level of morphinoids postoperatively and the very limited blood loss, there is no need for an urinary catheter during or after surgery. Patients can be orally fed 3–4 h after surgery. None of our patients need ICU monitoring postoperatively and almost all patients are dismissed the day after the surgery. Helmet therapy is started 2 weeks postoperatively.

Jimenez and Barone showed that the critical age for EACS seems to be 6 months.[ 22 ] After that age, the cosmetic results become worse and insufficient correction of skull shape is reached. However, one should not wait until the infant reaches the age of 5 or 6 months. The earlier an EACS is performed, the better the result. This is even more important in case of plagiocephaly and trigonocephaly. Therefore, below the age of 4 months, we always offer EACS as the treatment of choice, but for infants of 5 or 6 months, we restrict EACS for mild and moderate cases and consider open remodeling procedures for severe cases. We think that the optimal age to perform EACS is 3 months, as has been reported by other groups in the literature.[ 3 30 31 35 ] At this age, the child has grown and acquired some weight after birth, and both preterm and term infants have recovered from the physiological anemia which is most severe at approximately 8 to 12 weeks after birth in term infants. In preterm infants who are already born with a lower hematocrit, this decline, referred to as anemia of prematurity (AOP), occurs earlier and is more pronounced in its severity than the anemia seen in term infants. Therefore, at the age of 3 months, the child can tolerate some moderate blood loss and is able to tolerate the molding helmet. Unfortunately, we are often confronted with a diagnostic/referral delay by general practitioners and pediatricians, because of which patients are only presented to us at a later phase, often after the age of 3 months.

In syndromic cases, we aim for very early surgery at an age of 4–8 weeks, as we try to halt the progressive deformity, prevent intracranial hypertension, and simplify reconstructive surgery at a later stage. Parents are informed that cranial vault expansion and bifronto-orbital advancement procedures will still be required at a later stage. Because of the very young age and additional problems such as sleep apnea and risk of increased ICP, molding helmet therapy has not been added in these cases up to now.

Scaphocephaly

Patients are positioned in prone sphinx position, aligning the sagittal suture with the horizontal plane [ Video 1 ]. Two skin incisions of approximately 4 cm are used: one 2–3 cm behind the most posterior point of the anterior fontanel, and the second one 2–3 cm anterior of the posterior fontanel. From this skin incision, an osteoclastic craniectomy towards the anterior fontanelle and posterior fontanelle is performed using the high-speed drill and rongeurs after dissection and elevation of the periosteum [ Figure 2 ]. The length of this craniectomy can vary in case a part of the suture is still open and patent. After this, FloSeal® Matrix Hemostatic Sealant is administered for hemostasis. Then, the endoscope is introduced through the anterior skin incision and dura dissection from the overlying bone is performed. The perfect visualization of the dura and operative field by the endoscope in conjunct with a parallel positioned aspirator to clear any blood gives the surgeon total control of the operative field during this phase. Typically, in the middle to posterior part of the synostotic suture, several bridging veins running from the dura towards the bone can be identified and coagulated before rupturing. Hence, blood loss can be minimized and there is always perfect visualization of the dura and the underlying superior sagittal sinus. Once the dura dissection is completed, the periosteum is dissected and lifted from the suture. Bended bone cutting scissors are used to cut the bone strip from the posterior incision to the front, while the endoscope is used from the anterior incision to visualize and control the direction of cutting, protecting the underlying dura with the footplate. The removed bone strip should measure 4–5 cm wide. At this point, again FloSeal® Matrix Hemostatic Sealant is used covering the subcutaneous surgical field. Then wedge-shaped osteotomies are performed behind the coronal sutures and in front of the lambdoid sutures to assist in allowing an increase of the biparietal width. Periosteum, subcutis, and cutis are closed in separate layers using resorbable sutures, Steristrips (3M, Diegem, Belgium) included. A small compressive head bandage is used for 24 h.

Figure 2

3D scan showing extent of craniectomy in scaphocephaly. Thick black line indicates skin incision, grey area depicts craniectomy size

Trigonocephaly

Patients are placed in a supine position, aligning the metopic suture with the horizontal plane. One skin incision of approximately 3 cm is positioned symmetrically over the metopic suture just behind the hairline [ Figure 3 ]. The exact position of this incision depends heavily on the preoperative 3D CT scan and is always a trade-off between the (future) hairline and the curvature of the forehead. When the hairline demands an incision that is not favorable to overcome the curvature of the forehead with the endoscope, we recently started to use a small zig-zag incision. This allows more anterior displacement of the skin, and thus, a more anterior entrance to the epidural space with the endoscope and less difficulties in reaching the endpoint of the craniectomy just above the nasion.

Figure 3

3D scan showing extent of craniectomy in trigonocephaly. Thick black line indicates skin incision, grey area depicts craniectomy size

From this skin incision, an osteoclastic craniectomy towards the anterior fontanel is performed using the high-speed drill and rongeurs after dissection and elevation of the periosteum. The length of this craniectomy can vary in case a part of the suture is still open and patent. After this, FloSeal® Matrix Hemostatic Sealant is administered for hemostasis. Then, the endoscope is introduced and dura dissection from the overlying bone is performed. The perfect visualization of the dura and operative field by the endoscope in conjunct with a parallel positioned aspirator to clear any blood allows a safe dissection of the dura without the occurrence of dural tears although the frontal bone and synostotic suture often present with deep and sharp bony ridges. Typically, some bridging veins can be found near the most anterior part of the synostotic suture and can be coagulated before rupture. When performing dura dissection, the rigid scope tends to compress the dura as dissection advances anteriorly. Of course, it is of paramount importance to avoid too much pressure on the dura. Therefore, the entrance to the subdural space with the endoscope should be as anterior as possible to overcome the curvature of the forehead. Sometimes this will demand simultaneous progressive craniectomy of the suture while performing the dura dissection. Once the dura dissection is completed, the periosteum is dissected and lifted from the suture. A triangular craniectomy is performed with a base of 3 cm, tapering down between the orbits to just above the nasion, using the endoscope to protect the dura and provide good visualization. The bone near the skull base is generally more thick and cancellous, causing more venous bleeding. This can easily be controlled by using FloSeal® Matrix Hemostatic Sealant, and Ostene® bone wax. We recently added small wedge-shaped osteotomies pointed towards the upper lateral orbital edges to our treatment protocol. We think this might assist in the outbending of the flat area just above the lateral orbital edges in trigonocephaly. Periosteum, subcutis, and cutis are closed in separate layers using resorbable sutures, Steristrips (3M, Diegem, Belgium) included. A small compressive head bandage is used for 24 h. Facial and periorbital swelling is usually very mild.

Anterior plagiocephaly/brachycephaly

Patients are positioned in the supine position with the head contralaterally rotated in plagiocephaly cases or neutral position in brachycephaly cases. One (or two) curvilinear skin incision of approximately 3 cm wide is placed just behind the hairline over the synostotic suture(s). Depending on the hairline and the specific curvature of the forehead, we sometimes use a small zigzag incision (Harry Potter incision) to allow better skin retraction [ Figure 4 ]. From this skin incision, an osteoclastic craniectomy towards the anterior fontanel is performed using the high-speed drill and rongeurs after dissection and elevation of the periosteum [ Video 2 ]. The length of this craniectomy can vary in case a part of the suture is still open and patent. After this, FloSeal® Matrix Hemostatic Sealant is administered for hemostasis. Then, the endoscope is introduced and dura dissection from the overlying bone is performed up to the pterion. The perfect visualization of the dura and operative field by the endoscope in conjunct with a parallel positioned aspirator to clear any blood allows a safe dissection of the dura, without any problems with the middle meningeal artery branches. Once the dura dissection is completed, the periosteum is dissected and lifted from the suture. The synostotic suture is then removed with a width of 1–2 cm. At the pterion, some thick, cancellous bone can be encountered which may be responsible for some venous bleeding. This can easily be controlled by using FloSeal® Matrix Hemostatic Sealant, and Ostene® bone wax. Periosteum, subcutis, and cutis are closed in separate layers using resorbable sutures, Steristrips (3M, Diegem, Belgium) included. A small compressive head bandage is used for 24 h.

Figure 4

3D scan showing extent of craniectomy in plagiocephaly. Thick black line indicates skin incision, grey area depicts craniectomy size

Multisutural and syndromic craniosynostosis

Although our experience is small for multisutural, nonsyndromic cases, we adhere to the same rationale for performing ECAS in these cases as for monosutural synostosis. Jimenez and Barone have shown that nonsyndromic multisutural craniosynostosis can be treated successfully with excellent results and reversal of the deformities.[ 21 ] Therefore, we use the same timing and technique as in monosutural synostosis cases, including helmet therapy. Positioning depends on the affected sutures and is aimed at including all affected sutures within one sterile operative field. In general, all affected sutures are treated with suturectomy through one skin incision for every suture.

Recently, Jimenez and Barone reported on the endoscopic-assisted bilateral strip craniectomy of the coronal suture in an infant with Apert syndrome followed by helmet therapy.[ 15 ] Based on their experience and short-term follow-up, they stated that early endoscopic-assisted surgery may provide an alternate and safe surgical option to treat complex syndromic craniosynostosis, although long-term results are needed to evaluate this.

In our centre, we treated three Apert and two Muenke syndrome cases with EACS. However, we did so with a different goal than Jimenez et al. In syndromic craniosynostosis, we want to try to halt the progressive deformity, prevent intracranial hypertension, and simplify reconstructive surgery at a later stage by performing EACS in a very early stage (4–8 weeks of age) but without helmet molding therapy. This is a very easy and simple surgery with very low morbidity, but to our mind, it is not meant to be a replacement for conventional surgical techniques. It is rather a supplement treatment to reduce the burden of the syndrome on the infant until definitive reconstructive surgery can be performed at a later age. Some groups have started to perform posterior cranial vault expansion in a minimally invasive manner to achieve the same goal while waiting for the right time to perform definitive cranial vault reconstruction.[ 2 ]

Helmet therapy

To our mind, the success of EACS depends heavily on the cranial molding therapy. The helmet design, subsequent modifications, and compliance to the helmet therapy are all critical to the success of this procedure. The helmet has the ability to modify the calvarial growth pattern, and hence, the direction of growth in three dimensions. By controlling growth in most areas, the helmet focuses most of cranial growth in the areas where it is needed. By guiding the cranial growth in three dimensions, the fast developing and growing brain can act as a very effective internal distractor once suturectomy is performed. Without this guidance, e.g., due to lack of fit or noncompliance, cranial expansion occurs equally in all directions and the obtained correction after suturectomy remains incomplete.

One week after the surgery, a plaster imprint of the skull is taken, which serves as an initial template for the fabrication of the custom-made helmet and helmet therapy starts within 2 weeks after surgery. The helmet is designed to contact all areas of the cranium except where growth is desirable. Because the helmet needs to be worn 23 h daily, a perfect fit of the helmet is of paramount importance to prevent slippage or the development of pressure ulceration areas or other skin problems. Frequent follow-up by a dedicated orthotist and the craniofacial team, especially at the early stage of the therapy, ensures a perfect fit and allows for patient-specific adjustments in reaction to actual skull growth in three dimensions. This can be easily done by thermoplastic procedures until skull growth requires a new helmet. As the fastest increase in cranial volume occurs during the first two years of life, we aim for continuing helmet therapy until the age of 1–1.5 years or when normocephaly has been reached. In our series, the helmet was worn for 10 months on average.[ 6 ] Children needed 1 or 2 helmets in the beginning of our experience. As our procedure and the importance of early referral to our centre was slowly adopted by the healthcare system, we were able to shift the timing of the surgery more towards the age of 3 months. Being treated earlier, most children need now 2 to 3 helmets during treatment. As our experience with this procedure grew, we adjusted the design of the helmet in close collaboration with the orthotist. At this stage, we use two different types of helmet according to the involved suture. For scaphocephaly, a recently developed very light, one-piece resin helmet is used [ Figure 5 ]. This helmet has a thickness of only 6 mm and reaches very low at the back of the head and encloses the entire forehead. This allows for a perfect fit, no slippage, and no need for a chin closure. It has limited ability for thermoplastic adjustments and is somewhat stiffer, exerting a bigger force in anterior-posterior direction. With this helmet, we notice that occipital rounding of the head as well as frontal bossing tends to correct faster. However, this needs to be verified in the future with increasing patient numbers. For trigonocephaly, brachycephaly, and plagiocephaly, a two-piece plastic helmet is used [ Figure 5 ]. This helmet is slightly thicker, 8 mm, and allows the correction of the forehead as needed in these cases. Again, it reaches very low at the back of the head as well as at the nasion, without obstructing vision. This allows for a perfect fit, no slippage, and no need for a chin closure. This helmet is made of a thermoplastic material, allowing for more easy adjustments by heating. Especially in plagiocephalic cases, where asymmetry needs to be addressed, this allows for frequent adjustments according to the local skull growth, when the affected side is changing faster than the general growth of the skull. This resolves the need for constructing a new helmet for a local change, while still being able to guide local skull growth.

Figure 5

Helmets used for orthotic treatment. Left: 2-piece thermoplastic helmet used for trigonocephaly/anterior plagiocephaly. Right: one-piece resin helmet used for scaphocephaly

DISCUSSION

Recent reports focus on the embryological formation and premature closure of sutures as being the main pathogenetic cause for craniosynostosis to occur.[ 27 33 ] Thus, it starts with a prematurely closed suture and subsequently the resultant cranial deformity is mostly the result of compensatory overgrowth at adjacent sutures, as Delashaw showed in 1989.[ 5 ] This is a strong argument to try to perform surgery as soon as possible to interact and halt the further developing cranial deformity. To our mind, this is where technological advances make the difference; by using endoscopic techniques, the morbidity and mortality of surgery has dramatically dropped, allowing surgery in very young children. Technology can also overcome the shortcomings of simple suturectomy reported earlier. Based on Moss’ functional matrix theory, the brain can be used as a perfect internal distractor once suturectomy is performed, but it needs guidance.[ 28 ]

By using an orthotic molding helmet, the distractive forces of the growing brain can be guided towards the preferable growing vectors in three planes. We think that EACS with helmet therapy is the next logical step in the evolution of surgical techniques for craniosynostosis as it results from the combination of new insights into the pathogenetic mechanisms at play, together with the development of new technologies.

After having performed more than 140 cases, including all types of monosutural as well as complex nonsyndromic multisutural and some syndromic cases, we consider this technique as a very safe and valuable tool in the broad range of treatment possibilities for craniosynostosis, with satisfying results [Figures 6 – 8 ]. With our current experience, we actively advise this treatment to any craniosynostosis patient under the age of 4 months, but for patients aged 4–5 months with moderate-to-severe craniosynostosis (especially plagiocephaly and trigonocephaly), we inform parents that this treatment may not be sufficient and cranial vault reconstruction techniques may have to be performed at a later stage. Up to now, this was needed three times, of which one was for cosmetic reasons only. In this particular case of multisutural craniosynostosis involving the left coronal and sagittal suture, left plagiocephaly persisted after EACS and helmet therapy.[ 6 ]

Figure 6

(a and b) pre operative 3D fotogrammetry of a scaphocephalic patient. (c and d) 11 months postoperative 3D fotogrammetry of same patient. Frontal bossing has declined, occipital pointing is resolved, mid-parietal breadth normalized

Figure 7

(a and b) pre operative 3D fotogrammetry of a trigonocephalic patient. (c and d) one year postoperative 3D fotogrammetry of same patient. The width of the forehead is already increased, there is still some backslanting of the lateral brow

Figure 8

(a and b) pre operative 3D fotogrammetry of a patient with synostosis of left coronal and bilateral lambdoid sutures. (c and d)12 months postoperative 3D fotogrammetry of same patient. The cranial axis has almost completely aligned with the facial axis and the shape of the forehead is almost symmetrical, with perfect rounding of the occipital area

However, as experience grows and long-term follow-up data starts to be available in the literature, we think it is mandatory to evaluate the results of this technique by comparing them not only to historical data but also to other current techniques including both minimally invasive spring-assisted techniques as classical “open” techniques. Indeed, also classic “open” cranial vault reconstruction techniques have undergone some recent adjustments to reduce surgical time, blood loss, and morbidity. It is mandatory to try to evaluate whether EACS is suitable for all craniosynostosis cases, both nonsyndromic and syndromic, or only for selected subgroups.

The result of the EACS treatment depends heavily on the helmet therapy. This essential part of the treatment is often considered a major drawback of this treatment, some even call it a “complication” of this treatment (personal communication at VI World congress of Neuroendoscopy, Mumbai, 2013). In our series, helmet therapy was continued for a mean of 10 months (8–12 months). By using custom-made, very light helmets, the compliance rate of helmet therapy is very high and we never noticed pressure ulcers or major complications. In few cases, some eczema or dry skin developed, which resolved once helmet therapy was stopped. Up to now, we never had to stop helmet therapy because of intolerance. Overall, the “burden” of the helmet therapy, as reported by parents, seems to be very low. We tried to generate objective data on the burden of helmet therapy by sending an online questionnaire to all parents. The questions in the questionnaire covered all areas of the impact and were asked objectively. This does not rule out all bias, e.g., it can be that parents choosing a type of procedure are less likely to report that they made a mistake in choosing. Although only roughly one-third of all parents responded, results are mainly in favor for the helmet therapy. Almost everyone would choose again the EACS with helmet therapy and all respondents would advise others to choose this treatment.[ 6 ] This is in agreement with reports by other centers treating large numbers of patients with EACS.[ 3 17 18 35 ] However, the so called “burden” of the helmet therapy remains one of the main arguments to discard this treatment by those who have no experience with this treatment and are ill-informed.

When looking at the key points of this treatment, we still see room for future improvements:

- Patients need to be treated as early as possible, preferably just before or at the age of 3 months to get satisfying results. Therefore, early referral to the neurosurgeon is of paramount importance. Information and education of general practitioners, pediatricians, and paramedic professionals working with children with “abnormal” head shapes (physiotherapists, manual therapists, etc.) should be actively performed to raise awareness and enlarge the therapeutic time frame through early referrals.

- Although custom available surgical instruments are sufficient to perform EACS safely and successfully, development of dedicated instruments for this type of surgery can improve efficiency and reduce surgical time and blood loss even further. Especially the development of a new type of endoscopic shaft, small dedicated instruments for hemostasis, and a new design of a small craniotome that can be easily used below the skin under endoscopic guidance would improve surgical technique.[ 39 ]

- Helmet design can be further refined by using 3D CAD techniques. This could allow to construct the perfect molding helmet taking into account the actual skull compared to a reference “normal” skull to define the areas and extent of desired growth and/or restriction of growth. This would make the helmet therapy more reliable and predictable, with easier, planned, adaptations. This technique is already available but at the moment is more expensive than handmade custom helmets.

Last but not least, EACS may be combined with other surgical techniques as well. Spring expansion, internal and external distraction, and orbitofrontal advancement may all be combined with EACS, wherein the combination of two techniques allows further improvement of the result.

To our mind, the biggest challenge for the coming decades in the field of craniosynostosis surgery is trying to define which surgical technique or combination of techniques – open, endoscopic, spring-assisted – yields the best results in terms of satisfying cosmetic and functional results, with the lowest morbidity, mortality and cost, for certain set parameters such as craniosynostosis subtype, degree of severity, age at presentation, gender, and genetic background.

However, the field of craniosynostosis surgery is currently limited by the lack of objective data by which to interpret and compare results.[ 7 ] Comparison is often performed on subjective basis and biased by personal experience, teaching schools, training, and dogmas, although there are increasing efforts to develop objective tools to evaluate cosmetic outcomes. We agree fully with Hankinson et al. who stated “Until a satisfactory craniometric method or group of methods is established, it will be difficult to meaningfully compare the outcomes of the myriad operative techniques currently available for the treatment of single suture craniosynostosis,” and by extension multisuture craniosynostosis.[ 11 ]

CONCLUSION

We think EACS with molding helmet therapy offers an excellent alternative to traditional open approaches and should be considered for children diagnosed with nonsyndromic craniosynostosis prior to 3 months of age. Based on our very limited experience, we think it might also be a meaningful add-on therapy for syndromic cases to relieve the burden of the syndrome on the infant until definitive reconstructive surgery can be performed at a later age. In our experience, the helmet molding therapy is essential for reaching good results. This therapy is well tolerated by the children and parents alike without any major complications or concerns.

Financial support and sponsorship

Nil.

Conflicts of interest

None of the authors have any conflict of interest with publication of the manuscript or an institution or product that is mentioned in the manuscript and/or is important to the outcome of the study presented.

References

1. Anderson FM, Johnson FL. Craniosynostosis; a modification in surgical treatment. Surgery. 1956. 40: 961-70

2. Arnaud E, Marchac A, Jeblaoui Y, Renier D, Di Rocco F. Spring-assisted posterior skull expansion without osteotomies. Childs Nerv Syst. 2012. 28: 1545-9

3. Berry-Candelario J, Ridgway EB, Grondin RT, Rogers GF, Proctor MR. Endoscope-assisted strip craniectomy and postoperative helmet therapy for treatment of craniosynostosis. Neurosurg Focus. 2011. 31: E5-

4. Chan JW, Stewart CL, Stalder MW, St. Hilaire H, McBride L, Moses MH. Endoscope-assisted versus open repair of craniosynostosis: A comparison of perioperative cost and risk. J Craniofac Surg. 2013. 24: 170-4

5. Delashaw JB, Persing JA, Broaddus WC, Jane JA. Cranial vault growth in craniosynostosis. J Neurosurg. 1989. 70: 159-65

6. Delye HHK, Arts S, Borstlap WA, Blok LM, Driessen JJ, Meulstee JW. Endoscopically assisted craniosynostosis surgery (EACS): The craniofacial team Nijmegen experience. J Craniomaxillofac Surg. 2016. 44: 1029-36

7. Delye H, Clijmans T, Mommaerts MY, Vandersloten J, Goffin J. Creating a normative database of age-specific 3D geometrical data, bone density and bone thickness of the developing skull: A pilot study. J Neurosurg Pediatr. 2015. 16: 687-702

8. Faber HK, Towne EB. Early craniectomy as a preventive measure in oxycephaly and allied conditions: With special reference to the prevention of blindness. Am J Med Sci. 1927. 173: 701-11

9. Faber HK, Towne EB. Early operation in premature cranial synostosis for the prevention of blindness and other sequelae. Five case reports with follow-up. J Pediatr. 1943. 22: 286-307

10. Greene CS, Winston KR. Treatment of scaphocephaly with sagittal craniectomy and biparietal morcellation. Neurosurgery. 1988. 23: 196-202

11. Hankinson TC, Fontana EJ, Anderson RCE, Feldstein NA. Surgical treatment of single-suture craniosynostosis: An argument for quantitative methods to evaluate cosmetic outcomes. J Neurosurg Pediatr. 2010. 6: 193-7

12. Ingraham FD, Alexander E, Matson DD. Clinical studies in craniosynostosis analysis of 50 cases and description of a method of surgical treatment. Surgery. 1948. 24: 518-41

13. Jacobi A. Non nocere. Med Rec. 1894. 45: 609-18

14. Jane JA, Edgerton MT, Futrell JW, Park TS. Immediate correction of sagittal synostosis. J Neurosurg. 1978. 49: 705-10

15. Jimenez DF, Barone CM. Bilateral endoscopic craniectomies in the treatment of an infant with Apert Syndrome. J Neurosurg Pediatr. 2012. 10: 310-4

16. Jimenez DF, Barone CM. Early treatment of coronal synostosis with endoscopy-assisted craniectomy and postoperative orthosis therapy: 16-year experience. J Neurosurg Pediatr. 2013. 12: 207-19

17. Jimenez DF, Barone CM. Endoscopic technique for coronal synostosis. Childs Nerv Syst. 2012. 28: 1429-32

18. Jimenez DF, Barone CM. Endoscopic technique for sagittal synostosis. Childs Nerv Syst. 2012. 28: 1333-9

19. Jimenez DF, Barone CM. Endoscopic craniectomy for early surgical correction of sagittal craniosynostosis. J Neurosurg. 1998. 88: 77-81

20. Jimenez DF, Barone CM. Endoscopy-assisted wide-vertex craniectomy, “barrel-stave” osteotomies, and postoperative helmet molding therapy in the early management of sagittal suture craniosynostosis. Neurosurg Focus. 2000. 9: e2-

21. Jimenez DF, Barone CM. Multiple-suture nonsyndromic craniosynostosis: Early and effective management using endoscopic techniques. Clinical article. J Neurosurg Pediatr. 2010. 5: 223-31

22. Jimenez DF, Barone M, Cartwright CC, Baker L. Early Management of Craniosynostosis Using Endoscopic-Assisted Strip Craniectomies and Cranial Orthotic Molding Therapy. Pediatrics. 2002. 110: 97-

23. Lane LC. Pioneer craniectomy for relief of mental imbecility due to premature sutural closure and microcephalus. JAMA. 1892. 18: 49-50

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32. Sanger C, David L, Argenta L. Latest trends in minimally invasive synostosis surgery: A review. Curr Opin Otolaryngol Head Neck Surg. 2014. 22: 316-21

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40. Virchow R. Uber den Cretinismus, namentlich in Franken, und uber pathologische Schädelformen. Verh Phys Med Gesell Wurzburg. 1851. 2: 230-71

Abstract

Background:Gliosarcoma is a rare high-grade malignant tumor and a variant of glioblastoma characterized by biphasic glial and mesenchymal components. Gliosarcomas occur most commonly in the fifth or sixth decade of life and have a temporal lobe predilection. Occurrence in the pediatric population is extremely rare.

Case Description:Here, we report the case of an 8-year-old child with histologically confirmed gliosarcoma at the parieto-occipital lobe. Only a subtotal resection of the tumor mass could be performed in view of massive bleeding from the tumor bed; and despite postoperative chemotherapy and radiotherapy, the tumor recurred in a short span of time. A repeat surgery was done but the patient could not survive.

Conclusion:To our knowledge, this case constitutes the second youngest case reported in the literature with the lesion in the parieto-occipital region and the third youngest in all pediatric cases of gliosarcoma. This case demonstrates that possibility of gliosarcoma should always be kept in mind in children presenting with features of intracranial high-grade glial tumor. This case also suggests that significant residual after surgery is one variable that may affect the prognosis despite radiotherapy and/or chemotherapy.

Keywords: Brain neoplasm, glioblastoma multiforme, gliosarcoma, pediatric brain tumor

INTRODUCTION

Gliosarcoma (GS), a rare high-grade malignant tumor, is a variant of glioblastoma (GBM) characterized by biphasic glial and mesenchymal components.[ 8 ] It was initially considered to be a collision between two independent tumors where the sarcomatous component was believed to come from the proliferation of the vascular component.[ 4 ] In recent years, with the progression of genetic research, the occurrence of similar genetic alterations in both glial and mesenchymal components has suggested a monoclonal origin.[ 15 ] While the pathogenesis of GS remains poorly understood, several studies have identified shared mutations and cytogenetic abnormalities (including PTEN and p53 mutations, CDK4 and MDM2 amplifications, and p16 deletion) between gliomatous and sarcomatous elements of individual tumors, supporting a monoclonal origin involving inappropriate mesenchymal differentiation of gliomagenic cells.[ 1 18 ] The relative frequency of pediatric GS is 1.9% among GBM and 0.5% among pediatric central nervous system tumors.[ 14 ] To our knowledge, this case constitutes the second youngest case reported in the literature in the parieto-occipital region and the third youngest in all pediatric cases of GS.

CASE REPORT

An 8-year-old child was referred to our hospital for evaluation and management of a mass lesion at the left parieto-occipital region. The patient gave a history of generalized tonic–clonic seizure episodes for the past 2 months along with holocranial headache and intermittent vomiting. There was no history of any weakness of any side of the body. On examination, the patient was lethargic but conscious, oriented, and cooperative. Neurological examination was normal. Contrast-enhanced computed tomography (CECT) of the brain was suggestive of a contrast enhancing mass in the left parieto-occipital region having a solid cystic component [ Figure 1a ]. Magnetic resonance imaging (MRI) brain was suggestive of a large altered signal solid cystic mass lesion measuring 5.6 × 7.3 × 6.3 cm in the left parieto-occipital lobe extending into the left basal ganglia. The lesion showed heterogenous signal on T2/fluid-attenuated inversion recovery (FLAIR)/T1-weighted (T1W) images. Mass effect was seen as compression and effacement of the body and occipital horn of the left lateral and third ventricle and the splenium of the corpus callosum. There was significant enhancement of the mass following administration of intravenous gadolinium [Figure 1b - e ]. Based on these findings, a preoperative diagnosis of high-grade glial tumor was made.

Figure 1

(a) CECT brain showing solid-cystic contrast enhancing mass left parieto-occipital lobe. (b) T1W MRI brain and (c) T2W MRI brain showing heterogenous signal intensity. (d) Sagittal and (e) coronal cuts of contrast MRI brain showing avid contrast enhancement. (f) CECT brain obtained after surgical resection of the mass showing significant residual tumor. (g) T2W MRI brain done after 6 months of surgery showing recurrent tumor. (h) Postoperative CT brain showing residual tumor and tumoral bed hematoma

The patient underwent left parieto-occipital craniotomy and decompression of the mass. The tumor was found to have both solid and cystic component with the cystic part containing xanthochromic fluid. The solid part was grayish and firm in consistency and highly vascular with ill-defined plane of cleavage. Subtotal removal was performed in view of severe blood loss [ Figure 1f ].

Histology revealed highly vascular spindle cell tumor which was present in the form of sheets and fascicles. The cells had enlarged round to elongated nuclei, predominant nucleoli, and eosinophilic cytoplasm. Numerous mitotic figures, areas of necrosis, microvascular proliferation, and bizarre giant cells were seen. The cells were reticulin-rich and showed diffuse vimentin positivity and focal scattered glial fibrillary acidic protein (GFAP) positivity [Figure 2a - d ].

Figure 2

(a) H and E ×10 Gliosarcoma spindle cells in short fascicles with fibrillar background. (b) H and E ×40 showing numerous atypical mitosis. (c) Reticulin stain GMS ×10 showing numerous reticulin black fibers surrounding tumor cells. (d) Immunohistochemistry ×10 GFAP stain showing few islands of tumor cells as brown staining, rest sarcomatous components are stainless

Postoperative stay was uneventful and the patient was discharged on day 8. There was no neurological deficit and the patient improved symptomatically. As GS is known to spread extraneurally, CT abdomen and chest and MRI of the whole spine was done, which was negative. Concurrent chemoradiation of 60 Gy along with temozolomide 75 mg/m² on all days of radiation was given. However due to financial constraints, patient stopped taking temozolomide further.

Six months after the surgery, the patient returned with disoriented behavior, headache, generalized tonic–clonic seizure episodes, and bouts of vomiting. A repeat MRI was obtained which was suggestive of recurrent lesion [ Figure 1g ]. Re-exploration was done to decompress the lesion. However, massive blood loss prevented a gross total resection [ Figure 1h ]. Postoperatively, the patient remained on ventilatory support. The condition of the patient remained critical and he died on the 3^rd postoperative day despite aggressive management.

DISCUSSION

GS, defined as a variant of isocitrate dehydrogenase (IDH) wild-type glioblastoma, comprise 1.8–2.8% of glioblastomas and are rare biphasic tumors of the central nervous system, composing of alternating areas of glioblastomatous component admixed with sarcomatous component.[ 9 12 ] These tumors commonly affect adults in the fifth to sixth decades of life and are extremely unusual in children, with a male: female ratio of 1.4:1 to 1.8:1 and is traditionally associated with a dismal prognosis.[ 9 ] Twenty-five cases of pediatric GS have been reported in the literature, with a median age of 11 years and male: female ratio of 1.2:1.[ 17 ]

GS is characterized by alternating areas of glial and mesenchymal differentiation – a gliomatous component – which expresses GFAP and is reticulin free, and a sarcomatous component, which lacks GFAP expression and is reticulin rich. The recent theory of pathogenesis of GS suggests monoclonal origin of both components of GS with sarcomatous component originating via aberrant mesenchymal differentiation of the malignant glioma. This theory explains the absence of significant difference in the clinical outcome between GBM and GS.[ 6 ] The molecular mechanisms behind mesenchymal differentiation in gliosarcomas are not yet fully understood. Upregulation of epithelial–mesenchymal transition (EMT)- associated factors, such as Slug and Twist, have been reported in the sarcomatous component of GS, suggesting that EMT-associated factors may play a role in mesenchymal differentiation in gliomas.[ 10 ]

GS and GBM are considered to be two different pathologies with some studies showing a temporal lobe predilection for GS whereas others found no such difference.[ 6 12 ] In writing this case, the literature was searched to determine the reported cases of pediatric GS and it was determined that this case constitutes the second youngest case reported in literature with the lesion in the parieto-occipital region and the third youngest in all pediatric cases of GS. The youngest case reported was a 4-year-old child who also presented with tumor in the temporal lobe whereas the second youngest case reported was a 5-year-old child who showed tumor in the parietal lobe.[ 17 ]

The presenting signs and symptoms are consistent with those of rapidly expanding space occupying lesion such as headache and vomiting along with hemiparesis, seizures, and cognitive decline,[ 6 ] and are associated with an increased likelihood of dissemination and extracranial metastases.

On CECT scans, the lesions can appear with large necrotic areas and showing heterogeneous contrast enhancement, similar to GBM or as a hyperdense lesion with well-defined margins and showing homogenous enhancement, similar to that of meningioma.[ 20 ] On MRI, the signal intensity in T1 and T2-weighted imaging is variable and heterogeneous, generally hypointense in T1-weighted imaging and hyperintense in T2-weighted imaging compared to white matter. Sampaio et al.[ 16 ] found that the T2 hyperintensity components (excluding the necrotic cystic areas) had intense enhancement after contrast, supported by the current case.

The histologic features include fascicles of sarcomatous component, usually resembling a fibrosarcoma or malignant fibrous histiocytoma, interspersed with areas of typical glioblastomatous component, thus creating a biphasic arrangement. Some cases may show a distinctive epithelial histology showing squamoid or glandular appearances which are immunonegative for GFAP, thus creating not only diagnostic dilemmas but also management difficulties for the neurosurgeons regarding whether these areas represent metastasis or a primary manifestation of a high-grade glial neoplasm.[ 11 ]

Treatment options for GS include maximum safe tumor resection followed by postoperative radiotherapy and chemotherapy.[ 6 ] The median survival among all GS patients has been dismal, with an average of 9 months although there are some exceptions: it was noted that patients diagnosed prior to 50 years had a higher median survival period of 15 months as compared to 7 months for those diagnosed after age 50. Radical excision improves survival to 7–11 months compared to 4 months with biopsy alone. In the current case, radical resection could not be performed which lead to recurrence in a short span of time. Radiotherapy increases the survival rate from 4 months to 10 months, and one recent study found that higher total radiotherapy dose (at least 54 Gy) was associated with improved survival.[ 3 ]

Role of temozolomide (TMZ) as an adjuvant therapy in GS remains controversial. Two earlier studies found no significant survival benefit with TMZ[ 19 ] or TMZ-based chemoradiotherapy,[ 5 ] raising questions regarding the efficacy of TMZ toward gliosarcoma.[ 7 ] However, two recent studies found that TMZ-based chemotherapy was associated with significant survival benefit and beneficial prognostic significance (9.9 months with RT alone vs. 13.9 months with TMZ/RT;[ 2 ] 11.9 without vs. 21.2 months with TMZ.[ 13 ]

As with any tumors, total resection is of paramount importance for recurrence-free survival. However, in case of GS, this may not always be feasible as evident from the current case due to the high vascular nature of the tumor. Our patient had significant residual, and although postoperative RT and TMZ was administered, had recurrence in a short span of time; despite a repeat surgery, the patient could not survive. This may be a significant shortcoming of the treatment.

CONCLUSION

Although primarily a disease of the adult population, GS can rarely occur in pediatric group and this possibility should always be kept in mind in dealing with intracranial space occupying lesion in a child. Diagnosis and management can be clinically challenging with disheartening postoperative outcome due to its highly malignant behavior. More studies are needed to decide the best management option for childhood GS. Gross total resection should be attempted followed by postoperative radiotherapy and TMZ which may enhance patient outcome.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Actor B, Ludwig Cobbers JMJ, Büschges R, Wolter M, Knobbe CB, Lichter P. Comprehensive analysis of genomic alterations in gliosarcoma and its two tissue components. Genes Chromosomes Cancer. 2002. 34: 416-27

2. Adeberg S, Bernhardt D, Harrabi SB, Diehl C, Koelsche C, Rieken S. Radiotherapy plus concomitant temozolomide in primary gliosarcoma. J Neurooncol. 2016. 128: 341-8

3. Castelli J, Feuvret L, Haoming QC, Biau J, Jouglar E, Berger A. Prognostic and therapeutic factors of gliosarcoma from a multi-institutional series. J Neurooncol. 2016. 129: 85-92

4. Feigin I, Allen LB, Lipkin L, Gross SW. The endothelial hyperplasia of the cerebral blood vessels with brain tumors, and its sarcomatous transformation. Cancer. 1958. 11: 264-77

5. Han SJ, Yang I, Ahn BJ, Otero JJ, Tihan T, McDermott MW. Clinical characteristics and outcomes for a modern series of primary gliosarcoma patients. Cancer. 2010. 116: 1358-66

6. Han SJ, Yang I, Tihan T, Prados MD, Parsa AT. Primary gliosarcoma: Key clinical and pathologic distinctions from glioblastoma with implications as a unique oncologic entity. J Neurooncol. 2010. 96: 313-20

7. Lee D, Kang SY, Suh YL, Jeong JY, Lee JI, Nam DH. Clinicopathologic and genomic features of gliosarcomas. J Neurooncol. 2012. 107: 643-50

8. Louis DN, Ohgaki H, Wiestler OD, Cavenee WK.editors. Gliosarcoma. WHO classification of tumours of the central nervous system. Lyon: IARC; 2007. p. 48-9

9. Lutterbach J, Guttenberger R, Pagenstecher A. Gliosarcoma: A clinical study. Radiother Oncol. 2001. 61: 57-64

10. Nagaishi M, Paulus W, Brokinkel B, Vital A, Tanaka Y, Nakazato Y. Transcriptional factors for epithelial differentiation in gliosarcoma. Brain Pathol. 2012. 22: 670-6

11. Ozolek JA, Finkelstein SD, Couce ME. Gliosarcoma with epithelial differentiation: Immunohistochemical and molecular characterization. A case report and review of the literature. Mod Pathol. 2004. 17: 739-45

12. Parekh HC, O'Donovan DG, Sharma RR, Keogh AJ. Primary cerebral gliosarcoma: Report of 17 cases. Br J Neurosurg. 1995. 9: 171-8

13. Rath G, Sharma D, Mallick S, Gandhi AK, Joshi NP, Haresh KP. Clinical outcome of patients with primary gliosarcoma treated with concomitant and adjuvant temozolomide: A single institutional analysis of 27 cases. Indian J Cancer. 2015. 52: 599-

14. Ravisankar S, Chander RV, Devadoss PK. Pediatric gliosarcoma with fibrosarcomatous differentiation: Report of a rare case. Indian J Pathol Microbiol. 2012. 55: 521-4

15. Reis RM, Könü-Lebleblicioglu D, Lopes JM, Kleihues P, Ohgaki H. Genetic profile of gliosarcomas. Am J Pathol. 2000. 156: 425-32

16. Sampaio L, Linhares P, Fonseca J. Detailed magnetic resonance imaging features of a case series of primary gliosarcoma. Neuroradiol J. 2017. 30: 546-53

17. Savant HV, Balasubramaniam S, Mahajan V. Giant parietal lobe infantile gliosarcoma in a 5-year-old child. J Pediatr Neurosci. 2015. 10: 159-61

18. Walker C, Joyce KA, Thompson-Hehir J, Davies MP, Gibbs FE, Halliwell N. Characterisation of molecular alterations in microdissected archival gliomas. Acta Neuropathol. 2001. 101: 321-33

19. Walker GV, Gilbert MR, Prabhu SS, Brown PD, McAleer MF. Temozolomide use in adult patients with gliosarcoma: An evolving clinical practice. J Neurooncol. 2013. 112: 83-9

20. Zhang BY, Chen H, Geng DY, Yin B, Li YX, Zhong P. Computed tomography and magnetic resonance features of gliosarcoma: A study of 54 cases. J Comput Assist Tomogr. 2011. 35: 667-73

Abstract

Background:There is scant literature evaluating the indications, techniques, and outcomes of minimally invasive spine (MIS) surgery undertaken for pediatric and adolescent spine pathology. Our study attempts to evaluate the safe and effective use of MIS techniques in pediatric and adolescent patients and to appreciate the technical nuances of MIS surgery for this age group.

Methods:Consecutive pediatric and adolescent patients undergoing elective MIS lumbar procedures, from 2008 to 2016, were retrospectively analyzed from the practice of a single fellowship-trained academic spinal neurosurgeon. Information was retrieved regarding procedure and disease pathology. Descriptive data was obtained including age, sex, body mass index (BMI), insurance coverage, smoking status, and co-morbidities. Outcome measures were recorded including intraoperative complications, revision surgery, and return-to-function.

Results:Sixteen patients underwent 17 surgeries. The median BMI was 29.2 (range, 20.8–41.5). Age ranged from 12 to 19 years. Nearly 20% of the patients in our series were smokers. Most patients underwent discectomy, with L5-S1 being the most common level. One patient underwent direct pars defect repair and another underwent recurrent discectomy. More than 90% of the patients were complication-free at follow-up period of 6 months. One patient had a recurrent disc herniation and another had a superficial wound infection. Overall, 82.4% patients enjoyed full return to sports such as weight lifting, gymnastics, and contact sports. One patient required pain management to help alleviate ongoing pain. Another patient required a course of outpatient rehabilitation to help with a “foot drop.”

Conclusion:Our series illustrates the effective application of MIS techniques among carefully selected pediatric patients. Emphasis is on using a smaller (16 mm) tubular retractor and causing minimal disruption of paraspinal osseo-tendinous structures. MIS techniques can be successfully applied to the pediatric and adolescent age group.

Keywords: Adolescent spine surgery, direct pars repair, minimally invasive spine surgery, pediatric discectomy, pediatric laminectomy, pediatric spine surgery

INTRODUCTION

With the incidence of spinal pathology on the rise in the United States, spinal surgery options have also continued to diversify in both technique and application. In particular, minimally invasive spine (MIS) surgery has become increasingly popular for both decompression and instrumentation throughout the lumbar, thoracic, and cervical spine.[ 10 ] Advantages to minimally invasive spine surgery are readily apparent including smaller incisions, shorter hospital stays, less disruption of surrounding tissue, and reduced infection rates.[ 2 6 ]

MIS surgery was designed around, and has historically been applied to, the adult patient population.[ 6 10 ] There is a dearth of literature regarding the application of minimally invasive techniques to spinal pathology in the pediatric population with the exception of proposed application to scoliosis correction.[ 10 12 13 ] However, due to its minimal tissue destruction and targeted decompression, MIS shows great promise in appropriately selected pediatric patient cohorts.[ 4 ] Here, we illustrate the patient characteristics, operative technique, and surgical outcomes for minimally invasive lumbar spine surgery at our institution.

MATERIALS AND METHODS

Consecutive pediatrics and adolescent patients undergoing elective minimally invasive lumbar spine procedures were retrospectively analyzed from a single fellowship trained academic spinal neurosurgeon with privileges at both a private as well as a teaching hospital.

Information was retrieved regarding minimally lumbar invasive spinal procedure and disease pathology. Descriptive data was obtained regarding age, sex, height, weight, body mass index (BMI), insurance coverage, smoking status, or significant co-morbidities. Age range considered was any patient less than 19 years of age. The incorporation of patients up to the age of 19 was due to the fact that their clinical entity, conservative management, and work-up process for pathology likely began in the pediatric spectrum.

Years of surgeon experience and hospital practice setting (private versus academic) were abstracted. Outcome measures such as intraoperative complications, revision surgery, pain control issues, and return-to-function and physical activity were analyzed. A standard postoperative course of pain medication was determined as six weeks of by mouth narcotics prescribed by the neurosurgeon. Additional pain control was defined as any additional pain medication or pain-related issues treated by a primary care provider or neurosurgeon. Pain management indicates the need for pain management to become involved in the patient's long-term pain control.

Data was analyzed using appropriate statistical testing. Mean was considered with standard deviation. The use of range for age despite a mean presentation was intentionally used to show a better indication of spread and outliers in a smaller cohort.

Surgical technique

The procedure for pediatric discectomy is identical to the adult procedure, albeit with several caveats. First and foremost, emphasis is placed on minimizing muscle dissection and maintaining normal spine architecture. As such, a 16-mm tube is used as opposed to the typical 18-mm or 22-mm tube. The patient is placed prone on the Jackson spine table. Midline is marked with palpation of the spinous processes. A second line is marked 1.5 cm to the lateral midline for the corresponding side. The patient is prepped and draped in a standard sterile fashion. A 22-gauge spinal needle is used to localize the proper level on lateral fluoroscopy as well as to ensure a trajectory parallel to the disc space. A 22-mm incision is then made with sequential dilation using only the last two dilators to aide in subperiosteal dissection.

A proper 16-mm long tube is then inserted and fixated. Subsequently, a combination of monopolar and bipolar cautery is used to remove any additional muscle on the field. A high-speed drill and a combination of Kerrison rongeurs are used to free the bone and ligament from the nerve root. The disc is palpated and the nerve root is retracted safely. The disc is excised with a knife and pituitary rongeur with a partial annulotomy aided by an up-going and down-going curette. The nerve root is then palpated in all directions using a Woodson dissector. Hemostasis is achieved and the tube removed with direct visualization of bipolar coagulation of any muscle bleeding. The skin is closed with a deep fascia suture and several inverted 2-0 vicryl sutures. A skin glue is also used. Patients are generally discharged home the same day.

RESULTS

Descriptive data is shown in Table 1 . Sixteen individual patients underwent 17 MIS procedures. The split between male and female was relatively even with 56.3% of the patients being male. An average number of patients in our series were obese with a BMI of 29.4 with a standard deviation of 6.5 (range, 20.8–41.5; median BMI, 29.2). Ages ranged 12–19 with 16 being the mode with six patients presenting at that age. Most patients underwent discectomy with L5-S1 being the most common level. One patient had a direct pars defect repair and another had a recurrent discectomy.

Table 1

Descriptive data for minimally invasive spine surgery

Nearly 20% of the patients in our series were smokers including two patients under the age of 18. Three patients (18.8%) were on mood-related medications at the time of their surgery; two of those patients were on antidepressants.

Data involving operative outcomes is shown in Table 2 . The average follow-up period at which patients were seen in the clinic was 6 months. Nearly 90% of patients did not suffer a complication. One patient had a recurrent disc herniation and one patient had a superficial wound infection. No deep infections occurred. Overall, 82.4% (14/17) patients enjoyed a full return to sports such as weight lifting, gymnastics, or contact sports. One patient required pain management to help alleviate ongoing pain. One patient required a course of outpatient rehab to help with a foot drop pathology.

Table 2

Clinical outcome and complications of minimally invasive lumbar surgery in the pediatric and adolescent population

DISCUSSION

The rapid evolution of MIS surgery in the past decade has laid the ground for its applications in newer and more complex spinal pathologies.[ 7 ] Essentially, MIS defers from traditional spine surgery by laying stress on decreasing muscle crush injuries during retraction and avoiding the disruption of osseo-tendinous complex of paraspinal muscles.[ 4 ] By emphasizing on the above strategies, MIS aims to achieve the desired goals of spine surgery, while incurring minimal collateral damage to the bones, tendons, and muscles that actively control movement and contribute to the dynamic stability of the lumbar spine.[ 4 7 ]

As stated earlier, MIS has found applications in various pathologies dealt with by spinal surgery; however, nowhere do the abovementioned tenets of MIS seem more pertinent, or the application of MIS more relevant, than in the setting of pediatric spinal surgery. The developing bones, muscles, and tendons of the pediatric spine deserve to be operated upon with no or minimal disruption to prevent subsequent spinal deformity in this age group.[ 15 16 ] There are only a few studies describing MIS techniques in the pediatric population, especially for lumbar disc herniation (LDH).[ 9 10 12 13 ] Wang et al. documented the use of percutaneous endoscopic interlaminar discectomy in 29 pediatric patients and expounded the advantages (minimal traumatization and scar formation) in the utilization of MIS techniques for pediatric LDH.[ 13 ] Thomas et al. published their series of 6 pediatric patients undergoing MIS for LDH and stated that MIS techniques can be safe and efficacious in this patient population.[ 12 ] They, however, advocated the need for a larger series to validate their findings in pediatric patients. Our case series is one such attempt and represents the safe application of MIS surgery to the pediatric patient population requiring discectomy, laminectomy, or direct pars repair. We make the case for considering this approach as a standard of care in the pediatric and adolescent population.

Rationale for pediatric minimally invasive surgery

Spine surgery inherently causes damage to the surrounding muscles, which is evidenced by atrophy and subsequent loss of function in the paraspinal muscles.[ 1 4 ] The dissection and stripping of the tendinous attachment from the posterior elements of the spine results in the disruption of paraspinal muscle function, the most prominent of these being the multifidus muscle. The detachment of this muscle renders it incapable of dynamically controlling its motion segment. Use of electrocautery in dissecting the paraspinal musculature from the posterior spinous elements causes localized thermal injury and necrosis of the musculature, further weakening the function. The powerful self-retaining retractors rampantly used in traditional spinal surgery result in decreased intramuscular perfusion and muscle denervation (caused by damage to the neuromuscular junction following prolonged retraction), and are one of the foremost causes of paraspinal muscle necrosis. The severity of muscle disruption is correlated to the degree of the intramuscular pressure and the length of the retraction time. The clinical results correlate well with cadaveric studies that show minimally invasive, table-mounted tubular retractors produce lower retraction pressures in the surrounding soft tissues compared with traditional self-retaining open retractors.[ 11 ] This damage is relatively well-tolerated in the adult spine compared to the pediatric spine,[ 15 ] because any separation of musculature and tendinous structures from their osseous origins would hamper the dynamic stability of the pediatric spine.[ 12 13 ]

Salient features of our study

Our MIS strategy in the pediatric cohort lays emphasis on the use of specialized instruments tailored to the pediatric population and refined surgical techniques to limit paraspinal osseo-tendinous complex damage. Our series is unique in that smaller tube size diameter (16 mm versus the standard 22 mm) was used to minimize tissue disruption. By utilizing smaller tube sizes, less muscle and soft tissue disruption occurs, and therefore, may decrease postoperative surgical site soreness. We focused on operative technique and appropriate patient selection to achieve optimum results. Patients without acute presentation (foot drop) underwent a trial with conservative management. Clear pathology was linked to the operative indication, carefully documented, and discussed with patients and their families.

It worth noting in our series that the average patient undergoing a discectomy in our series was considered overweight with a BMI of 29.4. The BMI cut-off for frank obesity is at 30.0. This is not terribly surprising considering the adult obesity rate in Louisiana is approximately 36.2%. The obesity rate for 18–25-year old in Louisiana is 29.0%. For 10–17-year old, the rate was 21.0%. The average BMI across the country is 26.6 for males and 26.5 for females.[ 3 ]

After lumbar discectomy, studies have noted the following biomechanical changes in the disc space: decreased disc space height, increased intradiscal load, and subsequently increased facet joint loads, which may result in further back pain. Indeed, in our series, nearly 20% of the patients experienced pain needing additional management. Although through 1–6 years of follow-up, no patients needed instrumented fusion. Admittedly, this patient cohort should be followed for a long time for evaluation and management.

Disc herniation in the pediatric and adolescent population

Disc herniation has been described as a pathological process attributed to the degenerative disease of the spine.[ 12 ] Several biochemical, environmental, genetic, and mechanical factors have been described in the etiopathogenesis of disc degeneration. Compared to adult LDH, pediatric patients presenting with LDH have unique characteristics regarding clinical findings, radiology, and causes. Unlike adult LDH, which is mostly a consequence of chronic degeneration, pediatric LDH has been linked with trauma or injuries. Many of our patients were actively engaged in high intensity sports. This included gymnastics as well as weight lifting. Thus, multiple microinjuries of the intervertebral disc may have played a vital role in the etiopathogenesis of LDH in our series.

During a discectomy procedure, the overall goal is to remove herniated nucleus pulposis. The annular tear may be widened, if needed, to remove adequate disc material. While there is controversy regarding the proper extent of removal of herniated pulposis, it has been shown that more aggressive disc removal may lead to unfavorable biomechanics. Hence, pediatric LDH requires special consideration with respect to this aspect as aggressive disc removal may result in future degenerative problems for these patients. As such, especially in the pediatric population, great care should be taken to perform a less aggressive discectomy. This technique is followed in our institution.

Spondylolytic defects in young patients

A relatively common cause of lower back pain in adolescents is congenital pars defects. By having a defect in the pars, there is increased translated motion to the facet joints, thereby causing increased pain. Spondylolytic defects of the lumbar spine has traditionally been treated using a variety of techniques ranging from conservative management to fusion. Widi et al. demonstrated the efficacy of direct repair of the defect in young adult patients without significant disc degeneration and lumbar instability.[ 14 ] Our series has one patient who underwent a direct pars repair for spondylotic defect. Emphasis was placed on proper patient selection. The use of MIS technique resulted in the least disruption of spinal osseo-tendinous structures.

Several operative strategies have been advocated for direct pars repair, most notably wiring along with screw technique (Morscher hook screw, Buck screw). One biomechanical study noted that screw repair was consistently the strongest and most reliable repair method.[ 5 ] Operatively, at our institution, Buck screw placement is the accepted technique. Another method which has been described and is performed at our institution in selected cases is the application of allograft such as BMP for noninstrumented pars fusion. Direct pars repairs have been somewhat common in young adolescent athletes with intractable lower back pain. Some success has been reported with direct pars repair in this population.[ 8 ] Thus, we document the successful employment of MIS technique in the repair of a pars defect in a young athlete using allograft.

Complications

One patient suffered a superficial wound infection. This patient was successfully managed with a conservative course of oral antibiotics. The patient was followed up without further sign of infection. Of note, the patient had a BMI of 30.8 but otherwise no medical co-morbidities. One patient required a revision surgery for an early recurrent disc herniation. This patient had a BMI of 36.4. Initially, the patient tolerated the procedure of a L5-S1 disc herniation well and went home immediately postoperatively with good pain control. However, on postoperative day 4, the patient experienced acute onset of dramatic radiculopathy in a similar distribution but with higher intensity than preoperatively. The patient was not performing any heavy lifting or exercises. The patient underwent a revision surgery for a recurrent disc herniation and tolerated the procedure well.

Limitations

The present study has several limitations inherent to its retrospective nature. Information was limited by chart availability and short-term follow-up period of 6 months. Specifically, this incorporates operative decision planning and rubric for the entire conservative treatment algorithms. Furthermore, as indicated, one specific patient was lost to follow-up. While not abnormal in our patient population, this provides incomplete information regarding long-term operative outcome.

CONCLUSIONS

Technical advances in MIS allow for application to a wider patient population. Our series illustrates the safe and effective application of MIS techniques to carefully selected pediatric and adolescent patients. The emphasis during surgery should be on minimal tissue and biomechanical disruption for this patient population.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Gejo R, Matsui H, Kawaguchi Y, Ishihara H, Tsuji H. Serial changes in trunk muscle performance after posterior lumbar surgery. Spine. 1999. 24: 1023-8

2. Harrington JF, French P. Open versus minimally invasive lumbar microdiscectomy: Comparison of operative times, length of hospital stay, narcotic use and complications. Minim Invasive Neurosurg. 2008. 51: 30-5

3. W Last accessed on 2018 Nov 05. http://stateofobesity.org.

4. Kim CW. Scientific basis of minimally invasive spine surgery: Prevention of multifidus muscle injury during posterior lumbar surgery. Spine. 2010. 35: S281-6

5. Kip PC, Esses SI, Doherty BI, Alexander JW, Crawford MJ. Biomechanical testing of pars defect repairs. Spine. 1994. 19: 2692-7

6. O'Toole JE, Eichholz KM, Fessler RG. Surgical site infection rates after minimally invasive spinal surgery. J Neurosurg Spine. 2009. 11: 471-6

7. Phillips FM, Cheng I, Rampersaud YR, Akbarnia BA, Pimenta L, Rodgers WB. Breaking through the “glass ceiling” of minimally invasive spine surgery. Spine. 2016. 41: S39-43

8. Reitman CA, Esses SI. Direct repair of spondylolytic defects in young competitive athletes. Spine J. 2002. 2: 142-4

9. Sarwahi V, Horn JJ, Kulkarni PM, Wollowick AL, Lo Y, Gambassi M. Minimally invasive surgery in patients with adolescent idiopathic scoliosis: Is it better than the standard approach? A 2-year follow-up study. Clin Spine Surg. 2016. 29: 331-40

10. Sarwahi V, Wollowick AL, Sugarman EP, Horn JJ, Gambassi M, Amaral TD. Minimally invasive scoliosis surgery: An innovative technique in patients with adolescent idiopathic scoliosis. Scoliosis. 2011. 6: 16-

11. Stevens KJ, Spenciner DB, Griffiths KL, Kim KD, Zwienenberg-Lee M, Alamin T. Comparison of minimally invasive and conventional open posterolateral lumbar fusion using magnetic resonance imaging and retraction pressure studies. J Spinal Disord Tech. 2006. 19: 77-86

12. Thomas JG, Hwang SW, Whitehead WE, Curry DJ, Luerssen TG, Jea A. Minimally invasive lumbar microdiscectomy in pediatric patients: A series of 6 patients. J Neurosurg Pediatr. 2011. 7: 616-9

13. Wang X, Zeng J, Nie H, Chen G, Li Z, Jiang H. Percutaneous endoscopic interlaminar discectomy for pediatric lumbar disc herniation. Childs Nerv Syst. 2014. 30: 897-902

14. Widi GA, Williams SK, Levi AD. Minimally invasive direct repair of bilateral lumbar spine pars defects in athletes. Case Rep Med 2013. 2013. p. 659078-

15. Yasuoka S, Peterson HA, Laws ER, MacCarty CS. Pathogenesis and prophylaxis of postlaminectomy deformity of the spine after multiple level laminectomy: Difference between children and adults. Neurosurgery. 1981. 9: 145-52

16. Yasuoka S, Peterson HA, MacCarty CS. Incidence of spinal column deformity after multilevel laminectomy in children and adults. J Neurosurg. 1982. 57: 441-5

Commentary

1. Editor-in-Chief, Surgical Neurology International NYU Winthrop Hospital, NYU Winthrop NeuroScience/Neurosurgery, Mineola, NY 11501, USA. E-mail: nancy.epsteinmd@gmail.com

This study concludes that minimally invasive spine surgery (MIS) performed by a single fellowship-trained academic spinal neurosurgeon was both safe and effective based on a series of only 16 pediatric/adolescent patients. However, this claim is not adequately supported by these data. How could they conclude that 90% of patients had no complications at 6 postoperative months? They report that: 1 developed a recurrent disc, 1 had a superficial wound infection, 1 required continued pain management, and most critically, 1 had a foot drop. This is hardly what one should consider a good result. I submit that the appropriate conclusion is that MIS is contraindicated in the adolescent/pediatric age group. Had these patients undergone an open microscope-assisted procedure, they more likely than not, would have avoided at least 3 of the 4 complications, as there would have been enough room to maneuver to perform a more complete disc removal to avoid disc recurrence, and avoid inadvertent nerve root manipulation resulting in the residual pain syndrome and foot drop.

Abstract

Background:Bilambdoid and sagittal synostosis (BLSS), also called “Mercedes Benz synostosis,” is a multisutural craniosynostosis that has been described as a specific entity. However, this synostotic pattern can also be found in syndromic craniostenosis. To better define this entity we reviewed our experience with bilambdoid and sagittal synostosis.

Methods:We searched our prospective database for cases of bilambdoid and sagittal synostosis among all types of craniosynostosis. Two groups were distinguished – patients with isolated BLSS and the group of syndromic craniostenosis for whom BLSS was observed at initial presentation. We reviewed the clinical findings, associated diseases, and their management specifically for isolated BLSS patients.

Results:Thirty-nine patients were diagnosed with bilambdoid and sagittal synostosis among 4250 cases of craniosynostosis treated in our department over a period of 42 years. Among them, 8 were finally diagnosed as Crouzon syndrome. Of the 31 patients identified with isolated bilambdoid and sagittal synostosis, 25 (81%) were males and 6 (19%) were females. The average age at diagnosis was 17 months. At diagnosis, 16% of the population presented with papillary edema and 58% posterior digitate impressions. Two types of craniofacial dysmorphy were observed – a pattern with narrow occiput (71% of cases) and a pattern with dolichocephaly (29% of cases). Cerebellar tonsillar herniation was the most frequently associated malformation (61% of the isolated BLSS). Surgical management evolved during the years, and several surgical techniques were used to treat patients with BLSS, including isolated biparietal vault remodeling, posterior vault remodelling, and posterior vault expansion with internal or external distraction. In some cases, a craniocervical junction decompression was also performed. The mean follow-up was 82 months (7 years). The overall mental development was within normal limits in most children, but a mental delay was found in 25%.

Conclusion:Bilambdoid and sagittal synostosis constitute an isolated entity in almost 80% of the cases, whereas in the remaining 20% it is part of a faciocraniosynostosis syndrome. Two phenotypes may be found. Early surgical management is indicated, and several techniques can be used in this heterogeneous population. A cerebellar tonsillar prolapse is present in a majority of cases.

Keywords: Bilambdoid and sagittal synostosis, Chiari malformation, complex craniosynostosis, epidemiology, surgical strategies, outcome, papilledema

INTRODUCTION

Craniosynostosis occurs in one out 2000 live births.[ 8 ] In a majority of cases, the craniosynostosis is isolated, limited to a single suture, and without associated genetic anomaly. In one-fifth of the cases, it occurs as part of a genetic syndrome and often affects several sutures.[ 2 3 ] In such syndromic cases, most often both coronal sutures are involved. Apart from these two forms, another group can be described – a multisutural synostosis without an identified genetic syndrome that is usually referred to as “multisutural craniostenosis” or “complex craniostenosis.” This complex form of craniostenosis has been observed in one of every 20 cases of craniostenosis, and may occur in multiple combinations.[ 9 ] Because of the difficulty in defining identifiable subtypes in this complex group, little has been reported on multisutural craniostenosis.[ 18 ] However, it has been shown that these forms are associated with different brain anomalies, that they may require multiple surgical procedures, and that they are associated with developmental delay more frequently than the isolated forms.[ 4 5 7 ] For these reasons, complex cases may require a multidisciplinary team with craniofacial expertise. However, with the improvement of genetic techniques, this group is progressively reducing. In fact, new genes have been recently found to be involved in some cases such as TCF12 and ERF,[ 10 20 ] allowing a proper nosological identification. It should be noted that, in newly identified syndromes, regarding the classical craniofacial syndromes, the coronal sutures are most often involved.

In the present report, we retrospectively reviewed the complex synostosis not involving the coronal sutures, and in particular, the trisutural pattern of complex craniostenosis which presents with sagittal and bilambdoid involvement (BLSS).

Neuhauser et al. reported in 1976[ 17 ] the first series of 7 cases of craniostenosis with fusion of both lambdoid sutures and the sagittal suture associated with short stature and developmental delay;[ 1 2 16 ] they employed the term “craniofacial dysynostosis.” In 1998, Moore et al. introduced the term “Mercedes Benz” to define BLSS due to the characteristic appearance of the fused sutures on three-dimensional CT imaging.[ 15 ] The authors did not find an association with short stature.

Little is known about BLSS. It seems to be a heterogeneous disease. To better define this entity, we retrospectively searched in our prospective database cases of bilambdoid and sagittal synostosis among all types of craniosynostosis. This study represents, to the best of our knowledge, the largest published series of patients with BLSS. We reviewed the clinical findings, epidemiological data, associated diseases, and management for these patients and discuss the surgical strategy.

PATIENTS AND METHODS

Population

The study was conducted among consecutive patients with confirmed BLSS diagnosed between 1972 and 2014 at Necker Enfants Malades. We reviewed the clinical records, radiological findings, and their management.

The clinical diagnosis of bilambdoid and sagittal synostosis was confirmed on X-ray, skull computed tomography (CT), and for the most recent cases three-dimensional CT images, showing bilambdoid and sagittal synostosis with open coronal sutures.

RESULTS

Among 4250 cases of craniosynostosis treated in our department, 39 patients were diagnosed with bilambdoid and sagittal synostosis (0.9% of the global population) over a period of 42 years. The mean age at presentation was 23 months (3 days to 8 years). Eighty percent of this population was male. The trisutural pattern of craniostenosis was isolated in 31 cases (almost 80% of the cases), whereas a syndromic craniostenosis was identified in 8 cases (8 patients demonstrating during follow-up a clinical Crouzon syndrome which was genetically confirmed in recent patients). Papillary oedema was present in 6 cases at diagnosis (15% of the cases).

Isolated BLSS (n = 31)

Of these 31 patients identified with isolated bilambdoid and sagittal synostosis, 25 (81%) were males and 6 (19%) were females. The mean age at diagnosis was 17 months (4 days to 88 months). The age at diagnosis was less than or equal to 6 months in 52% of the cases. However, the mean age at diagnosis decreased over the years due to better recognition of craniofacial anomalies by pediatricians and improvement in radiological investigations. This trend was also shown by the increase in the number of patients diagnosed with BLSS during time [ Figure 1 ]. The mean paternal age was 36 and the mean maternal age was 30.

Figure 1

Evolution of the number of cases in time

Among them, 23 patients originated from Europe, 4 from Maghreb, and 1 from Sub-Saharan Africa. For 3 patients, data were unknown. One case of consanguinity was found but no additional family members with craniosynostosis were reported.

Two patterns of cranial features could be distinguished:

A pattern with narrow occiput in almost 71% of the cases [ Figure 2 ]: “short BLSS” with a coup de serpe. A frontal bossing was also associated in half of the cases

Figure 2

Three-dimensional CT showing bilateral lambdoid and sagittal synostosis with narrow occiput (“short BLSS”) in a posterior view (a) and a lateral view (b). We can notice concave occipital bone, severe posterior digitate impressions of the skull (a and b), and the descent of the cerebellar tonsils on sagittal CT scan reconstructions (c)

Figure 3

Three-dimensional CT scan showing a pattern of bilateral lambdoid and sagittal synostosis with dolichocephaly and occipital bossing (“long BLSS”) in a posterior view (a) and a lateral view (b) and T1 sagittal MRI exam showing a “long BLSS” pattern with moderate ventricles dilatation and small posterior fossa (c)

The clinical findings observed in BLSS are described in Table 1 .

Table 1

Phenotype in patients with isolated bilateral lambdoid and sagittal synostosis or “Mercedes syndrome”

Associated anomalies

At diagnosis, 16% of this population of BLSS presented papillary edema and 58% posterior digitate impressions. Multiple central nervous system (CNS) malformations were found in patients with BLSS. The most commonly reported were cerebellar tonsillar herniation, (19 patients; 61% of isolated BLSS population), enlarged bifrontal subarachnoid spaces (12 patients; 39% of the cases), venous anomalies (11 patients; 35% of the cases), enlargement of the cerebral ventricles (10 patients; 32% of the cases), syringomyelia (1 patient; 3% of the cases), microcephaly with bilateral deafness (1 patient; 3% of the cases), and gyration anomalies (1 patient; 3% of the cases) [ Table 2 ].

Table 2

Central nervous system associated anomalies found in our population of isolated BLSS

Though tonsillar herniation concerned almost two-third of the population, only 2 symptomatic cases were reported.

Similarly, though 32% of the patients presented with an enlargement of the cerebral ventricles, no cases of active hydrocephalus were found and no treatment was required.

Interestingly, the population of BLSS with cerebellar tonsillar herniation presented more commonly other anomalies such as ventricular dilatation compared to those without cerebellar tonsillar herniation. Over half of these patients with the association of ventricular dilation and cerebellar tonsillar herniation presented with symptoms that prompted a surgical decompression of the foramen magnum.

Extra-CNS malformations were also present in this population of isolated BLSS. One patient presented syndactyly of digit IV and V and low-set ears and another a brachydactyly. One patient presented multiple malformations with costal, vertebral, and urogenital malformations. Another patient presented isolated congenital urogenital malformation. No genetic syndrome was identified in these cases.

Surgical results

Of the 31 patients, 25 had reconstructive surgery (81%). The mean age at surgery was 21 months (3 months to 8 years). For 6 patients, no surgery was performed. Five patients were not operated because parents refused the treatment or because the child was considered too old due to a delayed diagnosis. In one child, due to severe hemorrhagic complication at the beginning of the procedure, the originally planned cranial remodelling was not performed and no second surgery was performed.

Two main types of cranial vault reconstruction were used in our experience – (1) posterior decompression and (2) parietal remodelling.

Posterior decompression was applied in 17 patients. All patients presented a “short BLSS,” i.e., the phenotype with occipital narrowing. In 11 patients, a parieto-occipital decompression without internal or external distraction was performed and a sagittal craniectomy was combined in 4 cases. Foramen magnum decompression was associated if tonsillar prolapse was observed (in 5 cases). For the most recent cases with occipital narrowing (6 cases), a parieto-occipital decompression with external distraction was performed without foramen magnum decompression [ Figure 4 ].

Figure 4

A schematic view of a “short pattern” of BLSS (a) and representation of the optimal surgical strategy in this type of BLSS, posterior craniectomy with external distraction (b)

Another type of cranial vault remodelling, parietal remodelling with sagittal craniectomy, was used in 8 patients [ Figure 5 ]. Six patients presented a “long BLSS,” i.e. the phenotypical pattern with dolichocephaly. This technique was also applied in two patients who presented a “short BLSS” with occipital narrowing, but at follow-up they showed an unsatisfactory outcome from a cosmetic viewpoint. In one of these two patients, there was a limitation of cranial vault remodelling because of hemorrhagic complications; hence, a second procedure was required with a posterior decompression. In the other case, a second procedure was needed because of a recurrence of signs of intracranial hypertension during the follow-up period.

Figure 5

A schematic view of a “long BLSS” (a) and the optimal surgical strategy for this type of BLSS, sagittal craniectomy with parieto-occipital remodelling (b)

In association with these two techniques of remodelling, a surgical decompression of the craniocervical junction was performed in 8 patients. In 6 cases, this decompression was performed during the same anesthesia for the cranial vault remodelling. In 2 cases, it was performed during a separate procedure (2 cases of symptomatic tonsillar herniation). One of these two symptomatic patients required a second procedure of craniocervical junction decompression because of development at follow-up of motor deficit and increase in the size of a syrinx cavity. This was a case of pattern of “short BLSS” with narrow occiput.

Surgical complications were observed in few patients. Dura mater tears were observed in 5 patients and local infection in one case. Major complications as venous sinus injury occurred in one case. Overall, of the 25 patients operated on, 3 required more than one surgery – 1 patient because of infection, 1 required 2 surgeries because of bad functional result after foramen magnum decompression, and finally a third patient required 3 operations due to hemorrhagic complications during the first procedure with limitation of cranial vault remodelling and because of bad aesthetic result after the second procedure.

Follow-up

The mean follow-up was 82 months (7 years). No additional synostosis was observed during the follow-up period. At the last follow-up, 8 patients (25% of patients) presented a moderate-to-severe developmental delay. In this population, 4 patients presented with a delay in diagnosis (age at diagnosis between 20 and 51 months) and one a surgical complication with notable limitation of cranial vault remodelling. Of the 4 patients with delayed diagnosis, 3 demonstrated severe signs of intracranial hypertension at diagnosis and the other microcephaly with no craniofacial surgery being performed.

Aesthetic result was considered good or excellent in 75% of the cases and insufficient in the rest of the cases. Insufficient aesthetic result required a second procedure in only one case.

Crouzon syndrome (n = 8)

Among the overall population of BLSS, a Crouzon syndrome was identified and genetically confirmed in 8 patients. Six patients were males and 2 were females. The mean age at diagnosis was 44 months (4–102). The mean paternal age was 37 years and the mean maternal age was 33 years.

DISCUSSION

BLSS is a rare pattern of complex craniostenosis. Only 39 cases were found among the population of 4250 craniosynostosis managed at Necker hospital between 1972 and 2014 (0.9%). Only 44 cases were reported in the literature.[ 1 2 3 12 13 14 15 16 17 19 ] The clinical features and surgical management of the published cases are summarized in Table 3 .

Table 3

Description of the 44 published cases of bilambdoid and sagittal craniostenosis

Interestingly, in our series, though 79% of the cases (31 patients) had an isolated BLSS, 8 children actually had a Crouzon syndrome (21%). In cases of Crouzon syndrome, no involvement of the coronal sutures was found at diagnosis or during follow-up. Because of the high incidence of this type of syndrome, a genetic testing should be considered in case of an infant with BLSS to rule out a FGFR2 mutation, allowing proper management and parental counseling.

Phenotypes

Two types of deformation can be distinguished in BLSS. The most frequent phenotype in our series was characterized by a relative brachycephaly with occipital narrowing – the “short BLSS.” A similar phenotype was observed by Neuhauser et al.[ 17 ] The second subtype was a scaphocephaly-like deformation with dolichocephaly and occipital bossing with little or no impact of the closure of the lambdoid sutures on the deformation (“long BLSS”). This subtype variation could be due to the time of onset of the lambdoid closure, localization of the lambda, and progression of the closure of the lambdoid and sagittal sutures. The possible scaphocephaly-like phenotype of a BLSS raises the question of the proper nosological identification based purely on the clinical appearance. This is an argument for the role of preoperative CT or X-ray in the preoperative evaluation of craniostenosis with dolichocephalic presentation, though such examination carries potential radiation-related risks. The use of nonirradiating methodologies to assess the patency of the lambdoid sutures, especially ultrasounds, should be promoted to allow proper identification of the “long BLSS.”

Associated anomalies

MRI remains the optimal imaging modality in the assessment of CNS-associated anomalies in this population. The patients in this study had evidence of cerebellar tonsil's herniation, venous anomalies, and ventricular enlargement, which are perhaps related to the significant bony abnormality associated to the fusion of the lambdoid sutures.

The most frequent associated CNS anomaly reported in our series was the tonsillar herniation presenting in 61% of isolated BLSS. Such an association between tonsillar herniation and craniofacial synostosis, first described in 1972 by Saldino et al.[ 21 ] is frequent in multisutural syndromic craniosynostosis,[ 4 ] though less common at diagnosis than initially reported in recent studies based on genetic confirmation of FGFR2 mutations (38.1% of the cases with Crouzon syndrome).[ 5 6 ] The physiopathology of such herniation could be explained by the premature fusion of the posterior cranial vault which would result in a disproportion between a small posterior fossa and hindbrain growth. However, it could also be explained by congenital anomalies of the cerebellum and brain stem.[ 4 ] As expected, a syrinx (1 case) and central apnea (2 cases) were observed in the group of patients with cerebellar tonsillar herniation. MRI is also useful during the follow-up period to evaluate the evolution of the tonsil herniation. Because radiological alterations may appear before the child becomes symptomatic, we added a routine MRI control in our follow-up examinations. Obviously, the follow-up assessments will be more frequent if symptoms of Chiari occur.

One-third of the patients presented a ventricular dilatation in our series. However, no active hydrocephalus was observed and no patient required a treatment for cerebrospinal fluid (CSF) disorders. Enlarged ventricles are frequent in complex craniostenosis. Two main pathogenic factors may explain the ventricular enlargement – a mechanically increased CSF outflow resistance due to compression of posterior fossa and a raised pressure secondary to venous outflow obstruction. These pathogenic mechanisms may coexist in BLSS.[ 23 ] As for syndromic cases, ventricular size is associated with the presence of tonsil's herniation.[ 6 22 ] In fact, enlarged ventricles were found in 8% of the cases without tonsillar herniation, but in 44% of cases with tonsillar herniation in our series. No difference was found between patients with or without cerebellar tonsillar herniation concerning the venous anomalies (present in 33% of each subgroup), although herniation of the cerebellar tonsils is associated in the literature with venous anomalies and venous hypertension.[ 12 ]

Venous anomalies such as jugular stenosis or thrombosis, lateral sinus compression, sagittal sinus compression, or hypoplasia of lateral sinus were found in 35% of isolated BLSS in our study.

Like other multisutural craniostenosis, BLSS can be associated with intracranial hypertension. In our series, 16% of the patients presented at the time of diagnosis a papillary edema and 58% posterior digitate impressions. This is another argument to better identify this pattern of craniostenosis for an early surgical management to prevent ophthalmologic and neurologic deterioration.

Surgical management

Several surgical techniques can be used in BLSS. The surgical management may differ according to the two phenotypic patterns. Indeed in “long BLSS,” i.e. dolichocephaly-like, the goal was shortening the anteroposterior length by opening the prematurely fused suture associated with biparietal remodelling. Conversely, in “short BLSS,” i.e. brachycephaly with occipital narrowing, the goal was skull elongation by posterior decompression with or without distraction. For all recent cases, a technique of external distraction osteogenesis was used. The use of external distraction (two or three) for calvaria vault expansion is a safe and efficient method offering the important advantage of controlling the vectors of distraction, and allowing gradual expansion. Furthermore, the distractors allow the child to rest supine in the postoperative period. This technique seems to be effective to treat the group of “short BLSS” with occipital narrowing.

The question whether to open the foramen magnum or not in asymptomatic patients is still debated. Despite a preventive early opening, there is a risk of secondary stenosis and symptom appearance during follow-up. Therefore, some authors have recommend to perform surgery after 12 months of life to reduce the risk of needing a new surgical procedure for a secondary stenosis of the foramen magnum with the argument that the likelihood of dural regeneration of bone would be lower at this later age.[ 8 ] However, delaying the cranial decompression carries the risk of increasing the cranioencephalic disproportion, thus aggravating the tonsillar herniation and, more importantly, increasing the risk of prolonged raised intracranial pressure and its consequences. For this reason, a surgical treatment was indicated in our recent cases before 12 months of age in all patients with BLSS independent of the tonsillar herniation.

Our study carries some limitations; because of the rarity of such a complex subtype, the period of the study was extremely long. Surgical and anesthetic procedures evolved during the last decades and as such reason; different techniques were applied in this population. Moreover, the rarity and heterogeneity of this complex craniostenosis hinder the possibility of randomized trials on large series to compare the different techniques.

CONCLUSION

We presented 39 cases of bilambdoid and sagittal synostosis (BLSS). This large series allow us to describe this entity and characterize the clinical features, evolution, and surgical management of this rare multisutural craniostenosis.

BLSS could be found in syndromic forms, i.e. Crouzon syndrome, underlying the importance of genetic testing. Nevertheless, in most cases in this series (31 cases), BLSS remained an isolated entity with no additional synostosis observed at follow-up analysis. Two main phenotypes can be found associated with trisutural synostosis – the “short BLSS” and the “long BLSS.” Because these children, especially when presenting with the latter phenotype, may be misdiagnosed, care must be taken to analyze the patency of the lambdoid sutures during clinical examination and on eventual radiological examinations (ultrasounds, CT, or MRI).

MRI evaluation is recommended in the management of these patients to identify associated anomalies and plan the surgical procedure. The most frequent associated anomaly is cerebellar tonsillar herniation. Venous anomalies and ventricles enlargement were also observed. Such a high incidence of tonsillar herniation in BLSS compared to other craniostenoses can be explained by the early involvement of lambdoid sutures and small posterior fossa. Early surgical correction seems to be required in this population of BLSS to try to reduce the risk of developmental delay.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Al-Torki NA, Sabry MA, Al-Tawari A, Al-Kandari NH, Al-Awadi SA. Craniofacial dyssynostosis with cryptorchidism and normal stature. Am J Med Genet. 1998. 79: 5-7

2. Bermejo E, Félix V, Lapunzina P, Galán E, Soler V, Delicado A. Craniofacial dyssynostosis: Description of the first four Spanish cases and review. Am J Med Genet A. 2005. 132A: 41-8

3. Bernardini L, Castori M, Capalbo A, Mokini V, Mingarelli R, Simi P. Syndromic craniosynostosis due to complex chromosome 5 rearrangement and MSX2 gene triplication. Am J Med Genet A. 2007. 143A: 2937-43

4. Cinalli G, Spennato P, Sainte-Rose C, Arnaud E, Aliberti F, Brunelle F. Chiari malformation in craniosynostosis. Childs Nerv Syst. 2005. 21: 889-901

5. Coll G, Arnaud E, Collet C, Brunelle F, Sainte-Rose C, Di Rocco F. Skull base morphology in fibroblast growth factor receptor type 2-related faciocraniosynostosis: A descriptive analysis. Neurosurgery. 2015. 76: 571-83

6. Coll G, Arnaud E, Selek L, Brunelle F, Sainte-Rose C, Collet C. The growth of the foramen magnum in Crouzon syndrome. Childs Nerv Syst. 2012. 28: 1525-35

7. Collmann H, Sörensen N, Krauss J. Hydrocephalus in craniosynostosis: A review. Childs Nerv Syst. 2005. 21: 902-12

8. Czerwinski M, Kolar JC, Fearon JA. Complex craniosynostosis. Plast Reconstr Surg. 2011. 128: 955-61

9. Di Rocco F, Arnaud E, Meyer P, Sainte-Rose C, Renier D. Focus session on the changing “epidemiology” of craniosynostosis (comparing two quinquennia: 1985-1989 and 2003-2007) and its impact on the daily clinical practice: A review from Necker Enfants Malades. Childs Nerv Syst. 2009. 25: 807-11

10. Fitzpatrick DR. Filling in the gaps in cranial suture biology. Nat Genet. 2013. 45: 231-2

11. Grosso S, Vivarelli R, Muraca MC, Berardi R, Marconcini S, Morgese G. Craniofacial dyssynostosis: Case report and review. Am J Med Genet A. 2004. 129A: 300-2

12. Hayward R. Venous hypertension and craniosynostosis. Childs Nerv Syst. 2005. 21: 880-8

13. Hing AV, Click ES, Holder U, Seto ML, Vessey K, Gruss J. Bilateral lambdoid and sagittal synostosis (BLSS): A unique craniosynostosis syndrome or predictable craniofacial phenotype?. Am J Med Genet A. 2009. 149A: 1024-32

14. Lahidji SF, Buchman SR, Muraszko K, Innis JW, Keegan CE. Craniofacial dyssynostosis in two boys with apparently normal cognitive development. Am J Med Genet A. 2006. 140: 1333-6

15. Moore MH, Abbott AH, Netherway DJ, Menard R, Hanieh A. Bilambdoid and posterior sagittal synostosis: The Mercedes Benz syndrome. J Craniofac Surg. 1998. 9: 417-22

16. Morton JE. Craniofacial dyssynostosis: A further case report. Am J Med Genet. 1998. 79: 8-11

17. Neuhäuser G, Kaveggia EG, Opitz JM. Studies of malformation syndromes of man XXXIX: A craniosynostosis-craniofacial dysostosis syndrome with mental retardation and other malformations: “Craniofacial dyssynostosis”. Eur J Pediatr. 1976. 123: 15-28

18. Renier D, Lajeunie E, Arnaud E, Marchac D. Management of craniosynostoses. Childs Nerv Syst. 2000. 16: 645-58

19. Rhodes JL, Kolar JC, Fearon JA. Mercedes Benz pattern craniosynostosis. Plast Reconstr Surg. 2010. 125: 299-304

20. Sharma VP, Fenwick AL, Brockop MS, McGowan SJ, Goos JAC, Hoogeboom AJM. Mutations in TCF12, encoding a basic helix-loop-helix partner of TWIST1X, are a frequent cause of coronal craniosynostosis. Nat Genet. 2013. 45: 304-7

21. Saldino RM, Steinbach HL, Epstein CJ. Familial acrocephalosyndactyly (Pfeiffer syndrome). Am J Roentgenol Radium Ther Nucl Med. 1972. 116: 609-22

22. Tamburrini G, Caldarelli M, Massimi L, Gasparini G, Pelo S, Di Rocco C. Complex craniosynostoses: A review of the prominent clinical features and the related management strategies. Childs Nerv Syst. 2012. 28: 1511-23

23. Vinchon M, Pellerin P, Baroncini M, Wolber A, Dhellemmes P. Non-syndromic oxycephaly and brachycephaly: A review. Childs Nerv Syst. 2012. 28: 1439-46

Abstract

Background:Expanding the posterior cranial vault has become a common procedure in the treatment of complex craniosynostosis. Several techniques are available to remodel the posterior vault. Aim of this study was to analyze the posterior vault distraction osteogenesis.

Methods:Between 2011 and 2014, 21 children (12 boys) were operated on for a posterior distraction of the cranial vault. The mean age was 8.6 months (minimum, 3 months; maximum, 15 years). Thirteen patients presented a craniofacial syndrome. Five had already been operated on (two anterior cranial surgery, two suboccipital decompression, and one craniotomy for sagittal synostosis). Raised intracranial pressure (ICP) was present in 6 patients. Seven patients had symptomatic cerebellar tonsils herniation (TH).

Results:In 17 children, 2 lateral distractors were placed, in 3 a 3^rd medial distractor was placed, and in 1 child 4 distractors were implanted. Volumetric analysis based on computed tomography showed a mean increase of volume of 13.9% 117 days later. After the distraction, symptoms related to raised ICP or TH were improved in all patients, however, radiologically TH was improved at the last follow-up in 54% of the cases.

Conclusion:Posterior cranial vault distraction is an efficacious technique to enlarge the posterior skull vault and treat increased ICP. Moreover, it appears to be efficacious in treating TH-related symptoms.

Keywords: Chiari, craniosynostosis, outcome, posterior cranial vault, skull remodeling, syndromic craniosynostosis

INTRODUCTION

Distraction osteogenesis of the craniofacial skeleton has several applications in the treatment of craniofacial malformations.[ 1 8 9 10 ] Distraction osteosynthesis is based on gradual, controlled separation of bone fragments at a rate that allows for progressive bone formation in the distraction gap created by an osteotomy. The standard distraction protocol, originally introduced by Ilizarov for extension of tubal bones, entails a latency phase of 5–7 days, a 1-mm/day distraction rate, and consolidation periods of one to several months.[ 6 ] This technology has the potential to generate bone in areas of skeletal hypoplasia such as the mandible and middle face. Further, it has been demonstrated to achieve larger bone advancements and a reduced rate of relapse compared to conventional techniques based on one-stage, immediate advancement, and osteosynthesis.[ 18 ]

The use of distraction osteogenesis involving the cranial vault was originally described for the frontal calvarium as part of monobloc advancements.[ 4 ] It has since been introduced as a technique to expand the posterior cranial vault.[ 10 21 ]

The purpose of this study is to review the current surgical technique and results of posterior cranial vault distraction in patients with craniosynostosis.

PATIENTS AND METHODS

Patients

Children submitted to posterior cranial vault expansion with distractors at the Craniofacial Unit, Necker Enfants Malades Hospital, over the period between September 2011 and July 2014, were included.

Surgical technique

The preoperative preparation, skin incision, and exposure of the skull were performed, as described in the previous article.[ 10 ] Two types of craniotomy were adopted – one was a supratorcular parieto-occipital craniotomy (supratentorial) and the other was an infratorcular craniotomy below the venous torcular (infratorcular), which were determined depending on the crowding of the posterior fossa, presence of tonsillar prolapse, preoperative assessment of the venous anatomy, and perioperative surgical findings. The osteotomy was performed with a motor drill or bone rongeur without elevating the cranial bone from the dura matter. Two to four distractors were applied depending on the age of the patient and the vector direction of the bone flap. If the patient had had a ventriculoperitoneal (VP) shunt implanted, the shunt was rerouted perioperatively. After surgery, the child was placed supine. Prolonged pressure of the skin over the distractors was avoided to reduce the risk of skin opening. The external part of the distractor was cut at the end of the skull expansion to avoid any risk of dislocation.

Psychological assessment

The level of anxiety of the parents generated by posterior distraction osteogenesis was also evaluated. Specific questionnaires were designed to measure at different time points of the postoperative period through ordinal scales parental anxiety related to (1) the surgery itself, (2) the use of the distractors and the distraction (the view of the latter, the ability to hold his child in the arms, the pain expressed by the child, etc.), (3) the return home and to school (the care of the scars, the way people look at the child, etc.), and (4) the morphological change (one week after surgery and few weeks after surgery). The questionnaires were given to the parents according to the date of surgery, and the answers were analyzed both quantitatively and qualitatively.

Data analysis

Volumetric analysis

Intracranial volume was calculated from computed tomography (CT) using Volume Viewer 2 medical imaging software (G.E. Healthcare, U.S.A) before and after distraction.

Evaluation of ossification

The degree of ossification of the bone defect on the osteotomy line after cranial vault expansion was evaluated clinically and on the CT performed at the time of removal of distractors. We divided the circle of the osteotomy defect into 10 parts. When more than half of one part was filled by new bone, we considered it as ossified. Therefore, the degree of ossification was counted by 10%, ranging from 0 to 100 percent.[ 12 ] Patients were classified into four groups as follows: “Absent” consisted of patients with 0–25% ossification, “poor” 26–50%, “fair” 51–75%, and “good” 76–100%.

Evaluation of tonsillar herniation

Cerebellar tonsillar herniation (TH) was evaluated in all patients according to sagittal MRI images or reconstructed CT. Patients were diagnosed as TH when cerebellar TH was more than 5 mm through the foramen magnum. Clinical symptoms before and after distraction and at the latest follow-up were noted.

Group classification

Patients were classified according to their underlying syndrome and genetic condition. They were divided into three groups as follows – (1) Group “CAP,” patients with Crouzon syndrome, Apert syndrome, and Pfeiffer syndrome. (2) Group “Other syndromes,” patients with Saethre–Chötzen syndrome, Muenke syndrome, and craniofrontal nasal dysplasia (CFND). (3) Group “complex,” patients without any genetic mutation in FGFRs, TWIST, or EFBN1.

RESULTS

Patient population

A posterior vault distraction was originally intended in 22 cases. However, in a child with a FGFR3-related Crouzon with acanthosis nigricans, because of a severe bleeding from emissary veins during the osteotomy, distractors were not inserted. This child was not included in the analysis. Thus, posterior distractors were implanted in a total of 21 patients.

Twelve of the patients were boys and 9 were girls. Signs of raised intracranial pressure were present in 6 patients. Distribution of age at surgery was from 3 months to 15 years; median age was 8.6 months. Two patients had a previous anterior craniotomy, 2 had suboccipital decompression for Chiari malformation, 1 had craniotomy for sagittal synostosis, and 16 patients had no previous craniotomy. Concerning the group 1, there were 7 patients (4 Crouzon, 2 Pfeiffer, and 1 Apert, syndrome), in group 2, 6 patients (3 Saethre-Chötzen syndrome, 2 Muenke syndrome, and 1 CFND), and in group 3, 8 patients. One patient of group “CAP” had a VP shunt implanted 12 years before occipital distraction that needed to be rerouted during surgery [ Figure 1 ].

Figure 1

Rerouting the shunt tube (Yellow triangles and a dotted line indicate the route of shunt tube). Upper figures are before rerouting, and lowers are after rerouting

Surgical procedure and complications

Thirteen of the 21 patients underwent supratorcular craniotomy and 8 infratorcular. The number of distractors was 2 in 17 patients, 3 in 3 patients, and 4 in 1 patient. One patient needed re-installation of distractors in the right side because of distractor malfunction. One patient needed to resuture the surgical wound 3 days after the ablation of distractors because of wound disruption. One patient had pneumonia postoperatively.

Distraction

Distraction started 3 days after implantation, 0.5–1.0 mm a day for 10–15 days. Mean duration between installation and ablation of distractors was 107 ± 32 days. Duration between installation of distractors and the CT evaluation was 117 ± 58 days.

Intracranial volume [ Figure 2 ]

Figure 2

Typical images on 3-dimensional reconstruction CT preoperatively (a), immediately after implantation of distractors (b), and 6 months after implantation (c)

The increase in intracranial volume was 132 ± 86 cc after distraction. The percentage of increase was 13.9 ± 11.9%. The earlier the surgery was performed, the more the intracranial volume augmented. According to symptomatic groups, median value of augmentation was 9.8% in the group “CAP,” 9.1% in the group “Others,” and 13.5% in the group “complex.” There were no significant differences among these groups. Between supratorcular and infratorcular craniotomy, there was no significant difference but there was a tendency of better expansion in infratorcular craniotomy [ Figure 3 ].

Figure 3

Augmentation of intracranial volume comparing between different craniotomies. The vertical axis indicates the percentage of augmentation of intracranial volume after the distraction

Ossification

An accurate evaluation of ossification could not be done clinically. However, CT scan analysis allowed us to precisely divide patients into four groups as follows – “absent,” 8 patients (0–25% ossification), “poor” (26–50% ossification) 5 patients, “ fair” (51–75% ossification) 5 patients, and “good” (76–100% ossification) 2 patients. The age at installation of distractors was 30.2 months in the group “absent,” 73.3 months in “poor,” 7.7 months in “fair,” and 21.8 in “good.” As expected, there was a tendency to ossify more in longer duration from installation of distractors to CT evaluation. However, surprisingly, there was no significant correlation between ossification and age at distraction [ Figure 4a ]. According to symptomatic groups, median rate of ossification was 20% in “CAP,” 60% in “others,” and 50% in “complex.” This indicated that the group “CAP” was less ossified than the other 2 groups [ Figure 4b ]. Patients who underwent supratorcular craniotomy were less ossified than patients who underwent infratorcular craniotomy (20% supratorcular vs. 60% infratorcular).

Figure 4

Evaluation of ossification of the bone defect on the osteotomy line. The vertical axis indicates the degree of ossification in each image. (a) Correlation between the age at surgery and the degree of the ossification (b) Comparison among syndromic groups

Evolution of tonsillar herniation

Thirteen of 21 patients were diagnosed as TH preoperatively. Two of 13 patients with TH had already undergone posterior decompression prior to distraction, but in 1 of 2 patients, the symptom had recurred. Seven patients had some symptoms preoperatively as follows – sleep apnea in 4, headache in 2, papilloedema in 4, and paresthesia in 1. The average value of TH was 8.3 mm before distraction and 8.1 mm at first control after distraction [ Figure 5 ]. Though there was no modification in the average measured TH, all patients were improved in their symptoms after distraction, regardless of their radiological change in TH [ Table 1 ]. Nevertheless, at last follow-up, TH was reduced in 7 of 13 patients (54%). There was no significant difference between supratorcular and infratorcular craniotomy. Two children with TH (17%) also had a cervical syrinx, which improved in both cases after distraction.

Figure 5

Typical images of TH on MRI of T1-weighted image, preoperative (a) and 14 months after distraction (b)

Table 1

Evolution of symptoms and TH

Psychological assessment

Eighteen parents agreed to answer the questionnaires. All parents, as expected, feared the surgical operation, the distraction, and their return home with the child having the distractors implanted. All parents were pleased to see that the children did not suffer during distraction. At first, they were all surprised by the aspect of the distractors on the head of their children and they needed some time to get used to them. One-third were in the beginning uncomfortable in handling their child, but they were finally at ease with the distractors in a few days. All parents could appreciate the morphological change induced by the distraction osteogenesis, and the return home and to school went well in all cases.

The concerns reported by some of the parents were mainly due to their feeling of lack of information concerning the distraction devices; only one-third of the parents felt completely satisfied with the information given ahead of surgery. Few parents reported that they would have liked to have had further details on the characteristics of the distractors, to know the recommended sleeping positions, and to know children's reactions to distractors.

DISCUSSION

Expansion of the posterior cranial vault was suggested to adequately increase the intracranial volume, avoid intracranial hypertension, and at the same time redirect the cerebral expansion posteriorly to prevent turricephaly.[ 21 ]

Initially practiced techniques for posterior cranial vault expansion were formal cranioplasty, with rearrangement and fixation of bone segments, either in the posterior aspect of the skull alone or as part of a combined anterior and posterior cranial vault expansion.[ 9 13 14 17 ] These techniques require complete separation of bone segments from the underlying dura mater, which is associated with risks for dural tears and hemorrhage from venous sinuses in the posterior cranial fossa. These risks have stimulated the development of less invasive techniques based on gradual posterior expansion without the need for extensive separation of bone segments from the dura mater. Sgouros et al. described the free-floating occipital release.[ 10 ] Subsequently, springs and internal distractors have been used for gradual expansion of the posterior cranial vault.[ 5 21 ]

Several techniques are available nowadays including[ 10 ] free-floating bone flap, fixed elevated bone flap without hardware, translambdoid springs, nonelevated bone flap, and hardware (spring or distractors).

The use of distraction osteogenesis involving the cranial vault was first described for the monobloc advancements,[ 4 ] and was subsequently used to expand other regions of the cranial vault.[ 2 ]

White et al. first described posterior cranial expansion with internal distractors in 2009.[ 8 ] Since then, other groups have confirmed the feasibility of this technique.[ 11 16 19 ]

Compared to springs, internal distractors share some risks of device-related complications:[ 10 18 22 23 ] (i) device loosening or breakdown and (ii) injury of the underlying dura mater by pins or screws. However, they also carry a potential infective risk due to the percutaneous components of the distractor. Because of the need of the osteotomy, they are associated to a greater hemorrhagic risk than translambdoid springs. Nevertheless, the morbidity of internal distractors was limited in our series to 1 child in whom the bleeding was severe, and distractors were finally not implanted and a free bone flap was performed.

Compared to translambdoid springs the distractor techniques allow obtaining a good control of the vectors depending on their placement and design of the craniotomy. The design of the craniotomy will decide the size of the bone flap and consequently affect the gain in intracranial volume as well as the change in posterior cranial shape. As for springs, there is a risk of hardware dislocation or dysfunction. Such complication occurred in one of our children leading to reoperation.

Though in the original description of this procedure the horizontal craniotomy was placed below the level of the torcula,[ 21 ] because of the risk for bleeding from venous sinuses in the posterior cranial fossa, we performed craniotomies above the torcula, as described by other authors[ 16 19 21 ] in 13 cases. The comparison of these two types of craniotomy shows differences in terms of size of bone flap as expected as well as in terms of volumetric gain but no significant differences in term of clinical or radiological efficacy.

The number of distractors used for posterior cranial vault expansion has varied from 2 to 4.[ 11 16 19 21 ] White et al. used 3 distractors in their case series, however, the authors discussed a modification of their protocol, reinforcing the distraction construct by adding a 4^th distractor, with the aim of enhancing the stability of the distraction construct and thereby reducing the rate of device-related complications.[ 21 ] However, use of multiple distractors is costly and increases the complexity of both distractor placement and removal. Indeed, the use of multiple distractors may increase the risk for introducing conflicting distraction vectors. Moreover, it could be argued that the risk for dural tears, infections, and other device-related complications would increase with the number of pins placed. In most cases, 2 distractors were sufficient to allow good expansion. We used a medial third when a caudal translation of the bone flap was also necessary to correct the shape of the skull vault. However, independent of the number of distractors used, in our series, no case of dural tear with CSF collection was found. The implantation of the third distractor on the midline over the sagittal suture resulted in a slightly more difficult procedure at the time of removal related to its relationship with the underlying superior sagittal sinus, but without increased morbidity.

Cerebral tonsils’ prolapse and posterior fossa crowding

Posterior cranial vault expansion has the potential to relieve any local compression on the brain in the posterior cranial fossa. In patients with progressive hydrocephalus, decompression of the subtentorial compartment should theoretically enhance CSF flow in the compressed cerebral aqueduct. Cinalli et al. reported that, in their experience, occipital remodelling and suboccipital decompression may fail to sufficiently restore normal CSF circulation.[ 3 ] Others reported improved CSF flow after cranial vault expanding procedures.[ 7 20 ] In our experience, posterior distraction resulted in the resolution of clinical symptomatology during the immediate postoperative period already within the first days of distraction even in cases where the osteotomy line remained over the torcula. Radiological evidence of syrinx regression and/or cerebellar tonsil's upward displacement was also found but only in 17% of children, though the number of patients is too little to draw definitive conclusions.

Indications and timing

Posterior cranial vault expansion is indicated in infants with syndromic and nonsyndromic craniosynostosis with a posterior flatness of the skull. In fact, though the posterior cranial flatness is usually less severe in nonsyndromic patients compared to complex multiple suture synostosis, bicoronal synostosis is still associated with an increased risk for raised intracranial pressure.[ 15 ] Thus, the strategy of first expanding the posterior cranial vault, before performing a fronto-orbital advancement at a later stage, is also a valid option for this group of patients.[ 10 ]

The procedure should be done early enough to prevent negative effects on brain development and further progression towards brachy-turricephaly. In most cases, a correction of the frontal region will be needed at a later stage.

Conversely, posterior expansion can also be used in old children, already operated on for the frontal region, who present with recurrent raised ICP or symptoms related to the posterior fossa crowding and descent of cerebellar tonsils. Because of the age of the patient and the limited effect that could be anticipated, we used internal distractors in old children. Though translambdoid springs are not used in our institution in children over 18 months, we can assume, by extrapolation of the volumetric effect according to age, that such springs cannot achieve an increase in volume as important as internal distractors. With this latter technique, we could obtain a resolution of the symptomatology (either raised ICP or brainstem compression) in all children of our series independent of age.

CONCLUSION

Surgical procedures aiming to expand the posterior cranial vault may be considered both in nonsyndromic and syndromic forms of bicoronal synostosis. Posterior cranial vault expansion offers large increase in intracranial volume, which may be needed to prevent intracranial hypertension in such patients. Further, by expanding the posterior cranial vault, local compression of the brain in the posterior cranial fossa may be relieved and progression of cranial dysmorphology towards turricephaly may be prevented. Moreover, an effect on the prolapse of the tonsils can be observed in some patients.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Arnaud E, Di Rocco F. Faciocraniosynostosis: Monobloc frontofacial osteotomy replacing the two-stage strategy?. Childs Nerv Syst. 2012. 28: 1557-64

2. Choi JW, Ra YS, Hong SH, Kim H, Shin HW, Chung IW. Use of distraction osteogenesis to change endocranial morphology in unilateral coronal craniosynostosis patients. Plast Reconstr Surg. 2010. 126: 995-1004

3. Cinalli G, Chumas P, Arnaud E, Sainte-Rose C, Renier D. Occipital remodeling and suboccipital decompression in severe craniosynostosis associated with tonsillar herniation. Neurosurgery. 1998. 42: 66-

4. Cohen SR, Boydston W, Hudgins R, Burstein FD. Monobloc and facial bipartition distraction with internal devices. J Craniofac Surg. 1999. 10: 244-51

5. Davis C, MacFarlane MR, Wickremesekera A. Occipital expansion without osteotomies in Apert syndrome. Childs Nerv Syst. 2010. 26: 1543-8

6. Ilizarov GA. Clinical application of the tension-stress effect for limb lengthening. Clin Orthop Relat Res. 1990. p. 8-26

7. Levitt MR, Niazi TN, Hopper RA, Ellenbogen RG, Ojemann JG. Resolution of syndromic craniosynostosis-associated Chiari malformation Type I without suboccipital decompression after posterior cranial vault release. J Neurosurg Pediatr. 2012. 9: 111-5

8. McCarthy JG, Schreiber J, Karp N, Thorne CH, Grayson BH. Lengthening the human mandible by gradual distraction. Plast Reconstr Surg. 1992. 89: 1-

9. Mofid MM, Manson PN, Robertson BC, Tufaro AP, Elias JJ, Vander Kolk CA. Craniofacial distraction osteogenesis: A review of 3278 cases. Plast Reconstr Surg. 2001. 108: 1103-

10. Nowinski D, Di Rocco F, Renier D, SainteRose C, Leikola J, Arnaud E. Posterior cranial vault expansion in the treatment of craniosynostosis. Comparison of current techniques. Childs Nerv Syst. 2012. 28: 1537-44

11. Nowinski D, Saiepour D, Leikola J, Messo E, Nilsson P, Enblad P. Posterior cranial vault expansion performed with rapid distraction and time-reduced consolidation in infants with syndromic craniosynostosis. Childs Nerv Syst. 2011. 27: 1999-2003

12. Oyama A, Arnaud E, Marchac D, Renier D. Reossification of cranium and zygomatic arch after monobloc frontofacial distraction advancement for syndromic craniosynostosis. J Craniofac Surg. 2009. 20: 1905-9

13. Persing JA, Jane JA, Delashaw JB. Treatment of bilateral coronal synostosis in infancy: A holistic approach. J Neurosurg. 1990. 72: 171-5

14. Pollack IF, Losken HW, Hurwitz DJ. A combined frontoorbital and occipital advancement technique for use in total calvarial reconstruction. J Neurosurg. 1996. 84: 424-9

15. Renier D, Lajeunie E, Arnaud E, Marchac D. Management of craniosynostoses. Childs Nerv Syst. 2000. 16: 645-58

16. Serlo WS, Ylikontiola LP, Lahdesluoma N, Lappalainen OP, Korpi J, Verkasalo J. Posterior cranial vault distraction osteogenesis in craniosynostosis: Estimated increases in intracranial volume. Childs Nerv Syst. 2011. 27: 627-33

17. Sgouros S, Goldin JH, Hockley AD, Wake MJ. Posterior skull surgery in craniosynostosis. Childs Nerv Syst. 1996. 12: 727-33

18. Shetye PR, Davidson EH, Sorkin M, Grayson BH, McCarthy JG. Evaluation of three surgical techniques for advancement of the midface in growing children with syndromic craniosynostosis. Plast Reconstr Surg. 2010. 126: 982-94

19. Steinbacher DM, Skirpan J, Puchala J, Bartlett SP. Expansion of the posterior cranial vault using distraction osteogenesis. Plast Reconstr Surg. 2011. 127: 792-801

20. Strahle J, Muraszko KM, Buchman SR, Kapurch J, Garton HJ, Maher CO. Chiari malformation associated with craniosynostosis. Neurosurg Focus. 2011. 31: E2-

21. White N, Evans M, Dover MS, Noons P, Solanki G, Nishikawa H. Posterior calvarial vault expansion using distraction osteogenesis. Childs Nerv Syst. 2009. 25: 231-6

22. Yonehara Y, Hirabayashi S, Sugawara Y, Sakurai A, Harii K. Complications associated with gradual cranial vault distraction osteogenesis for the treatment of craniofacial synostosis. J Craniofac Surg. 2003. 14: 526-8

23. Yu JC, Fearon J, Havlik RJ, Buchman SR, Polley JW. Distraction Osteogenesis of the Craniofacial Skeleton. Plast Reconstr Surg. 2004. 114: 1E-20E

Abstract

Background:With the greater worldwide availability of neuroimaging, more intracranial arachnoid cysts (IACs) are being found in all age groups. A subset of these lesions become symptomatic and requires neurosurgical management. The clinical presentations of IACs vary from asymptomatic to extremely symptomatic. Here, we reviewed the clinical presentation and treatment considerations for pediatric IACs.

Case Description:Here, we presented three cases of IAC, focusing on different clinical and treatment considerations.

Conclusion:IACs can be challenging to manage. There is no Class I Evidence to guide how these should be treated. We suggest clinical decision-making framework as to how to treat IACs based on our understanding of the natural history, risks/benefits of treatments, and outcomes in the future, require better patient selection for the surgical management of IACs will be warranted.

Keywords: Arachnoid cyst, neurosurgery, pediatric

INTRODUCTION

Richard Bright first reported medical cases in 1831 involving intracranial arachnoid cysts (IACs). These were found in patients from all age groups but mostly (75%) occurred in children.[ 9 ] IACs are composed of arachnoidal fluid-filled cysts which usually do not communicate with the ventricular system.[ 38 ] The majority are found incidentally and are generally considered asymptomatic; however, a subset of patients become symptomatic and require neurosurgical intervention. Symptoms from IACs may include headaches/increased intracranial pressure, hydrocephalus, local mass effect, or cyst rupture [ Table 1 ]. Local mass effect may contribute to focal neurological deficits dependent on the adjacent neural structures or bony anatomy (e.g., cortical thinning of the bone or “glacial change”). These lesions can also rupture, causing subdural hygromas or hemorrhage.

Table 1

Range of presenting symptoms

DIAGNOSTIC AND THERAPEUTIC CONSIDERATIONS FOR IACS

The growing availability of neuroimaging (MR, CT) worldwide has increased the frequency with which IACs have been diagnosed. With CT cisternography, they may be defined as communicating or noncommunicating with the subarachnoid space.[ 38 ] Treatment options include observation, medical management with acetazolamide, and surgical management utilizing fenestration and/or shunting with or without endoscopy.

EPIDEMIOLOGY

IACs occur in 2.6%of children and 1.4% of adults.[ 2 3 ] There is a male-to-female preponderance; ratios range from 2:1 to 5:1.[ 2 4 14 ] There is an increased incidence of IACs in conjunction with multiple genetic syndromes including autosomal-dominant polycystic kidney disease, acrocallosal, and Aicardi syndromes [ Table 2 ].[ 4 ] Although IACs occur throughout the neuroaxis, nearly half are found in the middle temporal fossa (MTF). Other common locations include the posterior fossa, the suprasellar region, and occasionally intraventricularly [Figures 1 – 4 ].[ 3 12 ] Most are incidental findings on neuroimaging studies (e.g., closed head trauma or headaches) and are asymptomatic. In a large pediatric series, they reported a 6.8% incidence of symptomatic IACs.[ 2 ]

Table 2

Neurological syndromes with increased incidence of intracranial arachnoid cysts

Figure 1

Large arachnoid cyst occupying majority left anterior and middle cranial fossae (Case 1). (a–c) Axial, coronal, and sagittal, respectively; coronal T2-weighted magnetic resonance imaging (MRI) of the brain demonstrating an arachnoid cyst eliciting extensive mass effect and 1 cm rightward midline shift. (d–f) Corresponding T2-weighted MRI 8 months postplacement of cystoperitoneal shunt demonstrating interval reduction of cyst size and corresponding midline shift

Figure 2

Large left middle cranial fossa arachnoid cyst (Case 2). (a and b) Axial and sagittal T1-weighted magnetic resonance imaging (MRI) of the brain demonstrating an arachnoid cyst eliciting extensive mass effect with sphenoid wing remodeling and distal left MCA branch displacement. (c and d) Axial and sagittal T1-weighted MRI of the brain 2 years after arachnoid cyst fenestration into the basal cisterns, displaying interval reduction in cyst size and decreased mass effect

Figure 3

Previously asymptomatic right middle and anterior cranial fossae archnoid cyst with subdural fluid collection (Case 3). (a and b) Coronal and sagittal T1-weighted magnetic resonance imaging (MRI) performed secondary to trauma demonstrated a previously asymptomatic archnoid cyst of the right anterior an middle cranial fossae. (c) Axial T2 MRI revealed small bilateral hemisphere CSF-isointense subdural fluid collections suggestive of cyst rupture. (d–f) Coronal, sagittal, and axial T2-weighted MRI performed on presentation to the emergency department 3 weeks after initial trial of conservative treatment. Interval development of extensive right hemisphere hygroma was seen producing midline shift with compression of the lateral ventricle

Figure 4

Right middle and anterior fossae arachnoid cyst with surgical resolution of traumatic hygroma (Case 3). Despite attempted management of hygroma development with cystoperitoneal shunt, symptoms persisted necessitating surgical fenestration of cyst walls, and regular follow-up was maintained. (a) Coronal T2-weighted magnetic resonance imaging (MRI) of the brain performed at 3 years postoperative follow-up demonstrated reabsorption of right hemisphere hygroma. (b) Sagittal T1-weighted MRI revealed interval reduction in arachnoid cyst-induced mass effect with reexpansion of cerebral sulci. (c) Axial T2-weighted MRI illustrated resolution of midline shift and relief of compression of the lateral ventricle

ETIOLOGY/PATHOGENESIS

IACs are congenital lesions, of unknown etiology. Previously, they were thought to result from gestational ischemic, traumatic, or infectious insults; these theories are no longer supported.[ 21 29 34 ] Others suggest that IACs arise from a congenital splitting of arachnoid membrane layers during fetal development, resulting in connected cerebrospinal fluid (CSF) entrapment and/or accumulation in this “potential space.” A more recent viewpoint for middle fossa IACs is that it was a failure of the frontal and temporal embryonic meningeal merging, resulting in a duplication within the Sylvian fissure.[ 36 ]

HISTOPATHOLOGY

Histopathologically, the arachnoid cyst (AC) wall consists of duplicated layers of normal arachnoid. However, ultrastructural examination demonstrates a split layer of abnormal arachnoid tissue characterized by hyperplastic arachnoid cells, increased collagen, and absence of the spider-like trabeculations characteristic of normal arachnoid.[ 28 ]

MECHANISMS OF IAC EXPANSION

Proposed mechanisms for IAC expansion include fluid diffusion down an osmotic gradient,[ 5 31 ] fluid secretion by cyst-lining cells,[ 13 16 ] and/or a one-way ball-valve mechanism pushing fluid into the IAC with CSF pulsations.[ 1 15 17 32 ] Halani et al. proposed a vessel-associated slit valve mechanism for IAC expansion in four pineal region ACs.[ 15 ]

CT AND MR-IMAGING CHARACTERISTICS OF IACS

CT and MR studies demonstrate that IACs are well-circumscribed, extra-axial, simple cystic lesions. They are isodense to CSF on CT, and isointense to CSF on all magnetic resonance image (MRI) sequences. Unlike dermoid or epidermoid cysts, they do not exhibit diffusion restriction on MRI and are not lobulated with heterogonous signal characteristic on MRI FLAIR imaging. Ruptured ACs can fill with blood products, resulting in imaging studies reflecting progressive blood degradation pathways. Chronic subdural hematomas or subdural hygromas can be isodense to CSF on CT. However, on MRI, they do not share signal characteristics of CSF. Rather they demonstrate enhancing membranes and morphology distinct from ACs (i.e., crescent-shaped layering along the cerebral convexities or layering along the falx or tentorium).

DIFFERENTIAL DIAGNOSTIC CONSIDERATIONS FOR IACS

Multiple other lesions must be differentiated for IACs. These include intraaxial cystic tumors (e.g., pilocytic astrocytomas or hemangioblastomas) that typically have a solid and/or enhancing components. Neurocystercercosis can also occur in the arachnoid space (racemose or “grape-like”) but usually comprises multiple cysts. Other differential considerations include a mega cisterna magna and other non-neoplastic cysts (e.g., neuroglial, neurenteric, or porencephalic cysts).[ 19 26 ]

GALASSI CLASSIFICATION OF MIDDLE TEMPORAL FOSSA IACS

MTF IACs account for more than half of all IACs [ Figure 5 ]. The widely used Galassi Classification (1982) provides a schematic radiological classification of these lesions [ Table 3 ].[ 10 ] There are three types of MTF IACs based on size and degree of mass effect. Type I cysts are characterized by the following: lens-shaped, anterior tip of the MTF, freely communicate with CSF/surrounding subarachnoid space on MR-cine/CT-ventriculography;[ 11 ] they rarely require surgery [ Table 3 ]. Type II cysts are characterized by intermediate size, more rectangular morphology, extend into the Sylvian fissure, have variable communication with CSF pathways, and exert local mass effect on the temporal lobe; they occasionally and sometimes require surgery. Type III cysts constitute the largest group, extend the full length of the Sylvian fissure, exert significant mass effect (often with midline shift), and do not communicate with the subarachnoid space; these usually require surgery.[ 4 10 38 ]

Figure 5

The incidence of arachnoid cysts in 309 children drawn from a sample of 11,738 consecutive MR imaging studies (Modified from Al-Holou WN, Yew AY, Boomsaad ZE, Garton HJ, et al. Prevalence and natural history of arachnoid cysts in children. J Neurosurg Pediatr 2010;5: 578-85)

Table 3

Galassi classification of middle cranial fossa arachnoid cysts^{[ 10 38]}

CLINICAL PRESENTATION: ASYMPTOMATIC VS. SYMPTOMATIC

Most IAC are asymptomatic and do not require surgery

Most IACs asymptomatic at presentation are incidental and do not require surgery; only 6.8% of large pediatric series show these patients are symptomatic.[ 3 ] The overwhelming majority of IACs do not change in size from the time of the initial diagnosis. These lesions only rarely expand in the pediatric population; when they do occur, they are primarily found in children under 4 years of age.[ 20 23 25 27 30 33 ]

SYMPTOMATIC HEMORRHAGE INTO IAC

Hemorrhage into IACs or rupture into the subdural space leading to subdural CSF hygroma or overt subdural hemorrhage can occur. Hemorrhage rates in the pediatric population are rare (0.3–6%).[ 7 23 ] Risk factors for hemorrhage include trauma and larger cyst size.[ 7 37 ] Although activity limitations for children with known IAC are debatable, many neurosurgeons recommend abstaining from contact sports.[ 35 ]

MULTIPLE INDICATIONS FOR IAC SURGERY

In patients with symptomatic IACs, the following variables may contribute to the need for surgery: IAC location, mass effect, impact on CSF flow dynamics (e.g., hydrocephalus), focal neurological deficits, headaches, seizures, and developmental/cognitive deficits [ Table 1 ].

Suprasellar IACs

Suprasellar IAC can result in compression of the hypothalamic–pituitary axis and thus in endocrinopathies, or of the Foramen of Monroe resulting in obstructive hydrocephalus.

Tectal IACs

Tectal compression from quadrigeminal plate IACs may be responsible for Parinaud's syndrome and/or obstructive hydrocephalus due to compressions of the Aqueduct of Sylvius.

CP angle and middle fossa IACs

Cerebellopontine angle IACs can cause progressive tinnitus, hearing loss, facial palsy, nystagmus, and/or vertigo, whereas MTF IACs can cause temporal/cranial remodeling, deformity, and distortion of orbit with proptosis. The decision for surgical intervention depends on the patient's symptomology.

TREATMENT APPROACH

The approach for treating IACs is summarized in Table 4 .

Table 4

Management approach

SMALL ASYMPTOMATIC IACS: NO SURGERY

The protocol for patients with small, asymptomatic IACs is the observation with or without repeat imaging. Symptomatic expansion occurs more commonly in children under 4 years or age; these patients warrant serial imaging. For those over the age of 4, symptoms alone may be followed.

SURGICAL INDICATIONS FOR IACS

Surgery is indicated in patients with symptomatic progression associated with hydrocephalus, focal neurological deficits, or localizable seizures. Additionally, large MTF cysts may remodel the overlying frontal, temporal, parietal bones, and/or the orbit resulting in disfigurement. Here, surgery may arrest this process and reduce associated symptoms (e.g., headaches).

DIAGNOSIS AND TREATMENT OF HEADACHES ASSOCIATED WITH IACS

IAC surgery for headaches remains controversial. Kershenovich and colleagues conducted a preoperative trial of acetazolamide to determine who would benefit from surgery; it benefitted 16 of 17 patients (e.g. 13 patients with resolution of symptoms, 3 improved).[ 18 ] Others have proposed invasive ICP monitoring to select patients for IAC surgery; here, the evidence remains unclear.[ 8 ]

SEIZURES CORRELATED WITH IACS

Some patients with IACs present with seizures. Improved seizure localization may help determine whether IAC surgery is warranted based upon video EEG monitoring, brain electrical source analysis, magnetoencephalography, ictal SPECT imaging, and interictal PET imaging. IAC surgery for poorly localized seizure activity remains controversial.

PROPHYLACTIC IAC SURGERY TO AVERT HEMORRHAGES

Prophylactic surgery has been proposed for very large IACs due to their increased risk of hemorrhage. Unfortunately, there is a lack of data regarding the natural history of these lesions and hemorrhage rates; prophylactic surgery, therefore, remains controversial.

SUBDURAL HYGROMA FROM IAC RUPTURE

IAC rupture can result in symptomatic subdural hygromas. They usually present within days to weeks following a rupture, with progressive elevated ICP (e.g. headache, emesis, CN VI palsy, or papilledema). Traditionally, surgery had been recommended in these patients.[ 6 ] There are, however, newer reports question this strategy.[ 22 ]

SURGICAL OPTIONS

There is no consensus regarding the optimal surgery for IACs. Two major surgical options for IACs include cyst shunting (cyst-peritoneal shunt) or cyst wall fenestration into surrounding CSF-filled spaces (cisterns or ventricles). Subdural hygromas or hemorrhages may be associated with IAC, requiring burr hole drainage, with/without fenestration or shunting.

CYST-PERITONEAL SHUNTING

Cyst-peritoneal shunting lowers ICP by CSF diversion, whereas fenestration does not change the CSF volume. Such shunting allows for expansion of the brain parenchyma, but there is no clear benefit unless there is elevated ICP. Nevertheless, this may result in shunt dependence along with its attendant complications. Shunting to the ventricle or subdural space has also been reported in the literature, but data regarding its safety/efficacy are limited.[ 9 24 ]

CYST FENESTRATION

IAC cyst fenestration avoids shunt-related issues and requires a small craniotomy or, more recently, endoscopic fenestration. The open approach offers the increased ability to control bleeding and perform surgery utilizing a bimanual microsurgical technique versus endoscopy.

BOTH SHUNTING AND CYST FENESTRATION OPTIONS FOR IACS

Fewel et al.[ 8 ] recommend both shunting and fenestration techniques for patients presenting with hydrocephalus. Some surgeons favor fenestration, with shunting reserved for fenestration failure.

CASE REPORTS SHORTEN AND CUT MARKEDLY

Case 1

A 14-month-old asymptomatic male, on CT, had a large left supratentorial hemispheric AC (12 × 5 cm, Galassi type 3) [Figure 1a – c ]. He was followed for 3–6 months with serial MRIs. At 6 months, he developed mild papilledema and the MR showed slight enlargement of the AC. A cystoperitoneal shun was placed. Eight-month postoperatively, the MRI demonstrated a significant reduction in the size of the AC, with decreased mass effect, and reduced midline shift (14–4 mm) [Figure 1d – f ]. He has remained asymptomatic without papilledema for how long?

Case 2

A 4-year-old male presented with vomiting and headache attributed to a Galassi type 2 MR-documented left middle fossa AC. Other comorbidities included global developmental delay (e.g., Trisomy 13 diagnosis), left ventricular noncompaction cardiomyopathy, GERD, a seizure disorder, and tethered cord. A later MRI showed further enlargement of the left middle cranial fossa AC (Galassi type 3) (6 months later) with remodeling of the adjacent sphenoid wing and more mass effect (e.g. increased midline shift) [Figure 2a , b ]. A lumbar puncture revealed an opening pressure of 43. A left temporal craniotomy was performed for fenestration of the AC into the basal cisterns. Postoperatively, the patient dramatically improved (e.g., resolution of headaches and emesis). The MRI 1 year later showed a significant decrease in the AC size (2.8 cm × 3.6 m × 3.5 cm compared to 6 cm × 4 cm × 4.5 cm preop) with reduced mass effect. At 2 postoperative years, the AC size was further diminished [Figure 2c , d ].

Case 3

A 12-year-old male presented with a 3-day history of severe headaches, blurry vision, and vomiting following a helmet-to-helmet collision at football practice. The initial CT and MRI imaging were consistent with a ruptured AC. These studies showed a large right middle cranial fossa AC (Galassi type 3), with remodeling of the adjacent skull, mass effect on the adjacent brain with midline shift medially, and bilateral 4 mm subdural effusions overlying the cerebral hemispheres [Figure 3a – c ]. He returned 3 weeks later with symptoms of increased ICP, and studies now showed increased mass effect from the right subdural hygroma with greater midline shift [Figure 3d – f ]. An emergent cystoperitoneal shunt was placed. He developed symptoms of overshunting, requiring shunt replaced with an external subdural drain. When severe headaches worsened by clamping the subdural drain, a surgical AC fenestration into the subdural space and basal subarachnoid cisterns was warranted. Transiently, a ventricular drain placed in the left large CSF space was removed without incident remained normal. Although he continues to have mild chronic headaches, he is now stable 3 years postoperatively [Figure 4a – c ].

CONCLUSION

There is no Class I evidence regarding the optimal treatment of IACs. We must, therefore, weigh the risks versus benefits of conservative versus surgical treatment of these lesions in symptomatic patients on an individual patient basis.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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Abstract

Background:Hemangiopericytoma and solitary fibrous tumor (HPC/SFT) are considered to be one category according to the WHO 2016 classification of central nervous system tumors. HPC/SFT are subdivided into infantile (congenital) and adult type. Both are extremely rare entities, with little knowledge about etiology, prognosis, and optimal therapeutic strategy.

Case Description:A 10-day-old girl was referred to our neurosurgical department due to hypotonia, palsy of the right oculomotor nerve, and prominent frontal fontanel. Imaging studies revealed a large occupying mass in the right middle cerebral fossa and the suprasellar cisterns. Only a subtotal resection of the tumor was possible, and postoperatively, she underwent chemotherapy (CHx). After a 3-year follow-up, the girl has minimum neurologic signs and receives no medications, and she can walk when she is supported.

Conclusion:Congenital HPC/SFT is considered to have a benign behavior with a good prognosis. Treatment with gross total resection, when it is feasible, is the key to a good prognosis and low rates of recurrence. However, there is no consensus on the therapeutic strategy of a HPC/SFT, which is difficult to be completely resected. Literature lacks a therapeutic algorithm for these tumors, and thus, more clinical studies are needed to reach a consensus.

Keywords: Congenital, hemangiopericytoma, intracranial, solitary fibrous tumor

INTRODUCTION

It is known that congenital brain tumors are very rare with an incidence of 1.1–3.6/100,000 newborns.[ 13 , 14 , 19 , 24 , 38 ] They make up 0.5%–1.5% of brain tumors that are diagnosed during infancy.[ 20 ] These neoplasms consist of teratomas, which are the most commonly found medulloblastomas, astrocytomas, choroid plexus papillomas, ependymomas, and hemangiopericytoma (HPC).[ 24 ] The latter is subcategorized to the adult type and the infantile (congenital) form, which is very rare, and only a few cases have been reported in the literature.[ 1 , 11 , 12 , 17 , 23 , 35 ] It usually has more benign characteristics than that of adults,[ 9 ] more often is highly responsive to CHx and has a better prognosis.[ 2 , 10 ] The latest WHO Classification of Tumors of the Central Nervous System (CNS) considers HPC a member of a group of lesions designated with the combined term hemangiopericytoma/solitary fibrous tumor (HPC/SFT),[ 4 , 21 ] which are usually located on brain surface. We present a case of an infantile anaplastic HPC/SFT.

CASE REPORT

A 10-day-old girl was referred to our neurosurgical department from the neonatal intensive care unit where it was being treated since her 3^rd day after birth due to jaundice. She presented with hypotonia, palsy of the right oculomotor nerve, and prominent frontal fontanel; a cerebral ultrasound and subsequently a computed tomography (CT) scan were performed and revealed a large hyperdense space-occupying mass in the right middle cerebral fossa and the suprasellar cisterns. Magnetic resonance imaging (MRI) demonstrated a tumor with marked inhomogeneous enhancement, with mixed cystic and solid components with dimensions of 6.7 cm × 6.2 cm × 6.1 cm [ Figure 1 ]. The tumor was occupying the right anterior frontal and medial cranial fossa along the entire right temporal lobe, extending to the frontal and parietal lobes, crossing the midline, infiltrating the cavernous sinuses bilaterally, and compressing the brain stem. Microsurgical resection of the tumor was performed on the 10^th day of her life through a right temporal craniotomy. Only a subtotal resection of the tumor was possible due to the size and the position of the tumor, the age of the patient, and the hemorrhagic tendency of the tissues involved. Histology report of the tumor revealed heterogeneous cellular density with cellular heterogeneity and regions with high mitotic activity 12–40/10HPF×40 (WHO Grade III) as well as regions with ischemic and apoptotic necrosis. The tumor was in continuity with the meninges with perivascular growth of neoplastic cells without neoplastic emboli. Gomori staining revealed HPC growth pattern. Molecular analysis by reverse transcription-polymerase chain reaction for hybrid gene ETS variant 6/neurotrophic tyrosine kinase, receptor, type 3 t(12;15) (p13;q25) was negative. In the immediate postoperative period, the baby presented with an increased tone of the left upper limp and nonreactive pupil. In the late postoperative period, she had an increase in her head circumference and a bulging frontal fontanel. A CT was performed, which revealed obstructive hydrocephalus [ Figure 2 ]. A ventriculoperitoneal shunt was inserted. In the immediate postoperative period, she presented with an improvement in the muscle tone of the upper limbs. Afterward, the child was referred to the oncology department and underwent CHx according to CWS guidance (version 1.5 from July 01, 2009) and received twelve cycles of Vincristine, Actinomycin D, and Cyclophosphamide, without any complications. Postoperative MRI scan after completion of CHx revealed regression of tumor to 3.5 cm × 3.5 cm × 3.8 cm [ Figure 3 ]. After a 3-year follow-up, the girl has no muscle weakness, normal tendon reflexes, and no Babinski sign. However, she continues to have a third nerve palsy. She crawls and can walk when she is supported, she can eat by herself, and she receives no antiepileptic treatment.

Figure 1

(a and b) Hemangiopericytoma and solitary fibrous tumor (HPC/SFT) in a 10-day-old girl. Left: Magnetic resonance imaging (MRI) axial postcontrast T1-weighted image of HPC/SFT, Right: MRI coronal of HPC/SFT. Postcontrast T1-weighted image.

Figure 2

Postoperative computed tomography scan with obstructive hydrocephalus after subtotal resection.

Figure 3

(a and b) Postoperative magnetic resonance imaging postcontrast T1-weighted image axial (left) and coronal (right) after completion of chemotherapy.

DISCUSSION

The incidence of congenital tumors is 0.34 per one million births, and infantile HPCs are extremely rare with an incidence of <1% of all CNS tumors.[ 29 ] Literature currently reports <20 cases[ 1 , 3 , 5 , 6 , 9 , 11 , 16 , 22 , 26 , 31 , 32 , 39 ] and differential diagnosis includes ependymoma, subependymoma, hemangioblastomas, fibrous tumors, or choroid plexus papilloma. Histological features place the diagnosis, where it should be stated that a cellular SFT is virtually indistinguishable from a HPC. For that reason, the two entities (HPC and SFT) are referred as one category in the latest CNS tumor classification of the WHO in 2016.[ 21 ]

In our case, the neoplasm shows morphological heterogeneity and is composed of cellular areas of the short bundles of spindle, stellate, and ovoid cells with eosinophilic cytoplasm and a round nucleus with fine chromatin without nucleolus and with mild-to-moderate nuclear atypia. A moderate-to-brisk mitotic activity of 12–40 mitoses/10 high-power fields (hpf) × 40 and 2–6 mitoses/hpf × 40 was recognized [ Figure 4a and b ]. Moreover, areas of moderate cellularity and areas composed of dissecting bundles of spindle cells with limited cytoplasm and limited mitotic activity along with wavy and storiform patterns are featuring. Furthermore, the focal myogenic morphology of the spindle cell bundles with focal nodular configuration and the presence of medium-sized veins with an epithelioid configuration of their wall must be delineated. Finally, spindle cells appeared to be either focal cleared or vacuolated, while epithelioid cells appeared with round morphology. Nevertheless, there was an extensive ischemic necrosis of up to 30% along with the presence of focal geographic apoptotic necrosis. Further immunohistochemical studies revealed that there was an expression of cytoplasmic/membranous cluster of differentiation (CD)34 in the stellate/spindle cells [ Figure 4c ]. A heterogeneous expression of smooth muscle actin was also seen in bundles of spindle cells and areas with myogenic differentiation [ Figure 4d ]. Diffuse expression of WT-1 protein along with heterogeneous expression of Factor XIIIa and focal expression of Cytokeratin 8.18 was also observed. However, there was no expression of CD31, erythroblast transformation-specific, human erythrocyte-type glucose transporter protein, Desmin S-100, glial fibrillary acidic protein, Synaptophysin Neurofilaments 2F11, and CD99/MIC-2. Proliferative index Ki-67/MIB-1 was detected in 15–30%, while INI-1/SMARCB1 expression was retained in >99% of the nuclei of the neoplastic cells. HPC/SFT share inversions at chromosome 12q13 and fused NAB2 and STAT6 genes. The latter fusion leads to the nuclear expression of STAT6 protein, which can be detected by immunohistochemistry. Considering mitotic activity, necrosis, and cellularity which are necessary criteria, our case was diagnosed with anaplastic HPC/SFT.

Figure 4

(a) Cellular areas of short bundles of spindle cells with an eosinophilic cytoplasm and a round nucleus with fine chromatin without nucleolus and with mild-to-moderate nuclear atypia. (b) Heterogeneous cellular density with cellular heterogeneity and obvious mitoses in a cellular area of the neoplasm. (c) Immunohistochemical expression of CD34 in the neoplastic cells mainly membranous and cytoplasmic. (d) A heterogeneous expression of smooth muscle actin in bundles of spindle cells.

In Table 1 , sixteen cases of HPC/SFT are recorded. The oldest publication is in 1954 from Peace, and since then, only a few cases have been added. Moreover, since then, the pathology has evolved and now plays a critical role in diagnosing HPC. The mainstay of treatment of HPC/SFT is considered to be complete excision, whenever it is possible.[ 10 , 27 ] In cases where complete excision was feasible, there was no evidence of recurrence after a follow-up of 1 month–5 years.[ 1 , 5 , 6 , 11 , 16 , 39 ] In case a gross total resection (GTR) cannot be performed, some have undergone CHx given the fact that infantile HPC/SFT is chemoresponsive.[ 8 , 25 , 34 , 36 ] CHx has been introduced as either initial treatment, to offer a chance for a GTR, or as a therapy in case of recurrence or incomplete resection.[ 8 , 16 ] Regiments used include combinations of vincristine, etoposide, doxorubicin, cisplatin, methotrexate, cyclophosphamide, actinomycin-D, and ifosfamide.[ 10 ] Radiotherapy (RTx) is also an option for primary or adjuvant therapy of infantile HPC/SFT.[ 25 , 33 , 39 ] Nevertheless, the effectiveness of RTx has been questioned as well as the long-term safety of the radiation dose. A recent study has found that there is no statistical significance in prognosis between GTR alone and GTR with RTx.[ 28 ] Moreover, a radiation dose of >50 Gray (Gy) has not been related to a good prognosis in HPC/SFT RTx, in contrast to the radiation dose of ≤50 Gy.[ 7 , 15 , 25 , 28 , 33 ] In general, the prognosis of infantile HPC/SFT is considered to be favorable,[ 2 , 10 , 27 ] and literature reports a 5-year overall survival of 80% for patients <1 year and 10-year overall survival of 62% for older patients.[ 10 ]

Table 1

Summarized congenital HPC at age of intervention. Sex, size pathology, complications, and follow-up are recorded.

CONCLUSIONS

Infantile HPC/SFT is considered to have a benign behavior with a good prognosis. Treatment with GTR is the key to a good prognosis and low rates of recurrence. Nevertheless, GTR is not always feasible. There is no consensus on the therapeutic strategy of a HPC/SFT, which is difficult to be completely resected. CHx before surgery has been proven useful, to make the tumor operable. Moreover, it has been successfully applied as an adjuvant therapy after surgery, or in case of recurrence. RTx has also been used in treating these tumors, but there have been studies that support its ineffectiveness. Literature lacks a therapeutic algorithm for these tumors, and thus, more clinical studies are needed to reach a consensus. In our case, a subtotal resection was performed, which was postoperatively complicated with obstructive hydrocephalus. After a ventriculoperitoneal shunt operation, the patient received CHx.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

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2. Bien E, Stachowicz-Stencel T, Godzinski J, Balcerska A, Izycka-Swieszewska E, Kazanowska B. Retrospective multi-institutional study on hemangiopericytoma in polish children. Pediatr Int. 2009. 51: 19-24

3. Blank W, Spring A, Giesen H, Artmann H. Intracranial hemangiopericytoma in a child. Klin Padiatr. 1988. 200: 422-5

4. Bouvier C, Métellus P, de Paula AM, Vasiljevic A, Jouvet A, Guyotat J. Solitary fibrous tumors and hemangiopericytomas of the meninges:Overlapping pathological features and common prognostic factors suggest the same spectrum of tumors. Brain Pathol. 2012. 22: 511-21

5. Cavalheiro S, Sparapani FV, Moron AF, da Silva MC, Stávale JN. Fetal meningeal hemangiopericytoma. Case report. J Neurosurg. 2002. 97: 1217-20

6. Cole JC, Naul LG. Intracranial infantile hemangiopericytoma. Pediatr Radiol. 2000. 30: 271-3

7. Coppa ND, Raper DM, Zhang Y, Collins BT, Harter KW, Gagnon GJ. Treatment of malignant tumors of the skull base with multi-session radiosurgery. J Hematol Oncol. 2009. 2: 16-

8. del Rosario ML, Saleh A. Preoperative chemotherapy for congenital hemangiopericytoma and a review of the literature. J Pediatr Hematol Oncol. 1997. 19: 247-50

9. Fernandez-Pineda I, Parida L, Jenkins JJ, Davidoff AM, Rao BN, Rodriguez-Galindo C. Childhood hemangiopericytoma:Review of st jude children's research hospital. J Pediatr Hematol Oncol. 2011. 33: 356-9

10. Ferrari A, Casanova M, Bisogno G, Mattke A, Meazza C, Gronchi A. Hemangiopericytoma in pediatric ages:A report from the italian and german soft tissue sarcoma cooperative group. Cancer. 2001. 92: 2692-8

11. Herzog CE, Leeds NE, Bruner JM, Baumgartner JE. Intracranial hemangiopericytomas in children. Pediatr Neurosurg. 1995. 22: 274-9

12. Hodaie M, Becker L, Teshima I, Rutka JT. Total resection of an intracerebral hemangioendothelioma in an infant. Case report and review of the literature. Pediatr Neurosurg. 2001. 34: 104-12

13. Jänisch W, Haas JF, Schreiber D, Gerlach H. Primary central nervous system tumors in stillborns and infants. Epidemiological considerations. J Neurooncol. 1984. 2: 113-6

14. Jellinger K, Sunder-Plassmann M. Connatal intracranial tumours. Neuropadiatrie. 1973. 4: 46-63

15. Jha N, McNeese M, Barkley HT, Kong J. Does radiotherapy have a role in hemangiopericytoma management?Report of 14 new cases and a review of the literature. Int J Radiat Oncol Biol Phys. 1987. 13: 1399-402

16. Kerl K, Sträter R, Hasselblatt M, Brentrup A, Frühwald MC. Role of neoadjuvant chemotherapy in congenital intracranial haemangiopericytoma. Pediatr Blood Cancer. 2011. 56: 161-3

17. Kirk IR, Dominguez R, Castillo M. Congenital primary cerebral angiosarcoma:CT, US, and MR findings. Pediatr Radiol. 1992. 22: 134-5

18. Laviv Y, Michowitz S, Schwartz M. Neonatal intracranial hemangiopericytoma:A 7-year follow-up. Acta Neurochir (Wien). 2012. 154: 637-8

19. Lee DY, Kim YM, Yoo SJ, Cho BK, Chi JG, Kim IO. Congenital glioblastoma diagnosed by fetal sonography. Childs Nerv Syst. 1999. 15: 197-201

20. Leins AM, Kainer F, Weis S. Sonography and neuropathology of a congenital brain tumor:Report of a rare incident. Ultrasound Obstet Gynecol. 2001. 17: 245-7

21. Louis DN, Perry A, Reifenberger G, von Deimling A, Figarella-Branger D, Cavenee WK. The 2016 world health organization classification of tumors of the central nervous system:A summary. Acta Neuropathol. 2016. 131: 803-20

22. McHugh BJ, Baranoski JF, Malhotra A, Vortmeyer AO, Sze G, Duncan CC. Intracranial infantile hemangiopericytoma. J Neurosurg Pediatr. 2014. 14: 149-54

23. Mena H, Ribas JL, Enzinger FM, Parisi JE. Primary angiosarcoma of the central nervous system. Study of eight cases and review of the literature. J Neurosurg. 1991. 75: 73-6

24. Nakayama K, Nakamura Y. Localization of congenital glioblastomas in the Japanese:A case report and review of the literature. Childs Nerv Syst. 2002. 18: 149-52

25. Pandey M, Kothari KC, Patel DD. Haemangiopericytoma:Current status, diagnosis and management. Eur J Surg Oncol. 1997. 23: 282-5

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30. Semerci SY, Demirel G, Vatansever B, Gundogdu S, Bolukbasi F, Oran G. Urgent surgical management of congenital intracranial hemangiopericytoma in a preterm neonate. Br J Neurosurg. 2017. 22: 1-3

31. Sobel G, Halász J, Bogdányi K, Szabó I, Borka K, Molnár P. Prenatal diagnosis of a giant congenital primary cerebral hemangiopericytoma. Pathol Oncol Res. 2006. 12: 46-9

32. Solitare GB, Krigman MR. Congenital intracranial neoplasm. a case report and review of the literature. J Neuropathol Exp Neurol. 1964. 23: 280-92

33. Staples JJ, Robinson RA, Wen BC, Hussey DH. Hemangiopericytoma the role of radiotherapy. Int J Radiat Oncol Biol Phys. 1990. 19: 445-51

34. Sultan I, Casanova M, Al-Jumaily U, Meazza C, Rodriguez-Galindo C, Ferrari A. Soft tissue sarcomas in the first year of life. Eur J Cancer. 2010. 46: 2449-56

35. Suzuki Y, Yoshida YK, Shirane R, Yoshimoto T, Watanabe M, Moriya T. Congenital primary cerebral angiosarcoma. Case report. J Neurosurg. 2000. 92: 466-8

36. Toren A, Perlman M, Polak-Charcon S, Avigad I, Katz M, Kuint Y. Congenital hemangiopericytoma/infantile myofibromatosis:Radical surgery versus a conservative “wait and see” approach. Pediatr Hematol Oncol. 1997. 14: 387-93

37. Voth D, Schröder JM, Gutjahr P, Stopfkuchen H, Kühnert A, Günther R. Intracranial hemangiopericytoma in a newborn (author's transl). Z Kinderchir. 1981. 32: 85-90

38. Winters JL, Wilson D, Davis DG. Congenital glioblastoma multiforme:A report of three cases and a review of the literature. J Neurol Sci. 2001. 188: 13-9

39. Wyler AR, Hered J, Smith JR, Loeser JD. Subarachnoid hemorrhage in infancy due to brain tumor. Arch Neurol. 1973. 29: 447-8

Abstract

Background:The Currarino syndrome (CS), defined by the triad of anorectal malformations, sacral bone deformities, and presacral masses, is rare. There are few surgical series that discuss conservative management versus the surgical approaches to these lesions. Here, we describe utilizing a combined anterior and posterior approach for resecting these lesions in four patients.

Methods:Four patients with CS were treated with two-stage approaches performed by a multidisciplinary team, including pediatric neurosurgery and general surgery. The first anterior laparoscopic approach mobilized the presacral mass from its ventral attachments. The second posterior procedure detethered the spinal cord, repaired the dural defect, and facilitated removal of the presacral mass.

Results:Gross total resection of all four presacral masses was accomplished without intraoperative complication; all patients clinically improved.

Conclusion:The CS is characterized by a large presacral mass. Here, one must rule out malignancy and also consider diagnosis/resection due to the risks for malignant transformation. The operative approach we described in four patients utilized standard anterior mobilization of the mass, followed by posterior detethering, dural repair, and ultimate resection.

Keywords: Currarino syndrome, presacral mass, tethered cord, ventral meningocele

INTRODUCTION

Currarino syndrome (CS) is a rare condition defined by a triad consisting of anorectal malformations, sacral bone deformities, and presacral masses.[ 2 , 7 ] Approximately 70% of cases are familial with an autosomal dominant inheritance pattern.

Although over 300 patients with Currarino’s triad have been reported/treated, there is no consensus regarding their optimal conservative versus surgical management.[ 3 ] Most surgeons plan their treatment based on the symptoms, physical examination, and radiographic findings. Conservative management may be an option if the patient is essentially asymptomatic despite the presence of sacral anomalies. Others recommend lesion resection due to the presence of symptoms/signs and/or risk of malignant transformation.

Different surgical approaches have been utilized.[ 2 ] Here, we report four sequential patients with symptomatic CS treated successfully with sequential, staged, anterior followed by posterior approaches.

CASE SUMMARIES

Four patients were included in this study [ Table 1 ]. They averaged 12.7 years of age and included two males and two females; the two males were brothers. A family history of anorectal malformation and neural tube defects was identified in three of the four patients. At the time of birth, three of the four patients had anorectal malformations, constipation, and pelvic pain, requiring surgical repair. Two patients (brothers) had a history of imperforate anus and tethered cord. One patient reported pain with forward flexion at the hip, and another reported severe menstrual cramping.

Table 1

Summary of demographic and clinical characteristics.

Magnetic resonance studies and surgery

An magnetic resonance (MR) imaging scan was obtained on all patients and revealed presacral masses with sacral defects. All underwent a combined anterior/posterior approach performed by a multidisciplinary team including pediatric neurosurgery and general surgery. The pathology revealed each patient had both a sacral meningocele and teratoma. Only one patient had a perioperative complication consisting of a superficial wound infection treated successfully with antibiotics. Patients were followed an average of 8 postoperative months, by which time all exhibited improvement in their symptoms including the resolution of pelvic pain. Further, constipation resolved completely in one patient and improved but persisted in the other three. None demonstrated delayed neurological deterioration.

SUMMARY OF OPERATIVE TECHNIQUE

Anterior approach

Each patient was initially positioned supine, and laparoscopic access was obtained to the presacral mass. It was carefully dissected away from surrounding structures, with care taken to identify and preserve both ureters. The dissection was taken down to the anal canal and the levators. Following sufficient mobilization of the meningocele, the abdominal wounds were closed, and the patient was turned prone.

Posterior approach

Midline dissection was carried down to the sacrum where multiple sacral laminectomies were performed. A midline durotomy was created inferior to the level of the most caudal exiting nerve root. Detethering was achieved by sectioning the filum terminale. Next, the thecal sac was circumferentially dissected, allowing for identification of the fistula, leading to the anterior sacral meningocele. The dissection was then extended below the coccyx into the presacral space, where it was ventrally mobilized from the posterior sacrospinous ligaments and ultimately fully resected.

DISCUSSION

Patients with CS most commonly present with severe constipation after birth.[ 5 , 8 ] This is often due to an enlarging presacral mass. It most commonly includes an anterior sacral meningocele, enterogenous cyst, tethered cords, and/or teratomas (e.g. found approximately 50% of the time, with the potential for malignant transformation).[ 1 ]

The female-to-male ratio of CS is 2:1 in children and 6:1 in adults. The increased female predominance in adults may be partially due to the frequency of CS diagnosed for patients presenting with dysmenorrhea (e.g., patient 2). About >50% of patients with CS have a mutation of HLXB9 located at 7q36; such mutations have been observed in up to 90% of familial-associated CS.[ 4 ]

Utilizing a comprehensive, multidisciplinary team (oncology, pediatric surgery, and pediatric neurosurgery) and two-staged anterior/posterior surgical approaches, four patients with CS successfully underwent total resection of these lesions without any adverse events. We advocate early operative intervention for multiple reasons. First, symptoms can be improved with surgery. Second, early surgical intervention limits the risk of future, spontaneous rupture of the teratoma, resulting in meningitis, spinal abscesses, and/or malignant transformation. Third, surgical resection provides an accurate, confirmatory pathologic diagnosis.[ 6 ]

CONCLUSION

CS is a rare condition associated with a triad of findings. Symptomatic sacral masses should be promptly treated with anterior followed by posterior surgical resection. This provides an immediate pathologic diagnosis, while gross total resection can be safely accomplished without significant neurological injury. Alternatively, waiting and watching may result in not only a delay in diagnosis and the risk of malignant transformation but also increases the risk of permanent neurological injury.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Barwick K. Anorectal presacral and sacral tumors. Gastroenterology. 1987. 92: 2046-7

2. Chakhalian D, Gunasekaran A, Gandhi G, Bradley L, Mizell J, Kazemi N. Multidisciplinary surgical treatment of presacral meningocele and teratoma in an adult with currarino triad. Surg Neurol Int. 2017. 8: 77-

3. Colombo F, Janous P, Buxton N. Carcinoid transformation of presacral dermoid cyst in patient with currarino syndrome:A case report. Br J Neurosurg. 2017. 14: 1-2

4. Crétolle C, Pelet A, Sanlaville D, Zérah M, Amiel J, Jaubert F. Spectrum of HLXB9 gene mutations in currarino syndrome and genotype-phenotype correlation. Hum Mutat. 2008. 29: 903-10

5. Emans PJ, Kootstra G, Marcelis CL, Beuls EA, van Heurn LW. The currarino triad:The variable expression. J Pediatr Surg. 2005. 40: 1238-42

6. Isik N, Elmaci I, Gokben B, Balak N, Tosyali N. Currarino triad:Surgical management and follow-up results of four correction of three cases. Pediatr Neurosurg. 2010. 46: 110-9

7. Kirks DR, Merten DF, Filston HC, Oakes WJ. The currarino triad:Complex of anorectal malformation, sacral bony abnormality, and presacral mass. Pediatr Radiol. 1984. 14: 220-5

8. Köchling J, Pistor G, Brands SM, Nasir R, Lanksch WR. The currarino syndrome hereditary transmitted syndrome of anorectal, sacral and presacral anomalies. Case report and review of the literature. Eur J Pediatr Surg. 1996. 6: 114-9

Abstract

Background: Medulloblastoma is the most common malignant brain tumor in the pediatric population. Despite prognosis improvement in the past two decades, one-third of the patients still remain incurable. New evidence suggests that medulloblastoma comprises four distinct entities; therefore, treatment de-escalation is required. The aim of this article is to evaluate epidemiological data from patients treated at our institution. The primary objective is to analyze overall survival (OS) and event-free survival (EFS) and the secondary objective is to identify prognostic factor from this cohort.

Methods: We retrospectively analyzed 69 patients who underwent surgical resection for medulloblastoma among 423 children from the tumor registry data bank of Santo Antônio Children’s Hospital from 1995 to 2016. Kaplan–Meier method and Cox regression analysis were used to identify OS, EFS, and prognostic factors.

Results: The 5-year OS and EFS rates found were 44.5% and 36.4%, respectively. The extent of resection and radiotherapy as adjuvant treatments was positively correlated to outcome while metastatic disease at diagnosis was negatively related to OS. Age younger than 3 years old did not have a worse outcome in our cohort.

Conclusion: Similar results to population-based studies were found, but we still face difficulties due to living in a developing country. In the near future, we look forward to new diagnostic techniques that will enable us to classify medulloblastomas according to molecular subgroups.

Keywords: Childhood medulloblastoma, Event-free survival, Gross total resection, Overall survival, Prognostic factors

INTRODUCTION

Medulloblastomas are the most common malignant tumor of the central nervous system (CNS) in children.[ 14 ] They account for 20% of the brain neoplasms in the pediatric population and are classified as embryonal tumors according to the World Health Organization (WHO) classification system. In the United States, medulloblastoma incidence is around 5.07 children per million and they have a bimodal peak at 3–4 years old, and then again at 8–7 years old.[ 12 , 16 ] Epidemiological data in Brazil are rare, and the real incidence of this tumor is not known. In a large series of pediatric tumors in an oncology reference center in São Paulo, medulloblastoma prevalence was around 13%.[ 19 ]

These tumors occur in the posterior fossa and they grow into the IV ventricle or in the cerebellar hemisphere leading to obstructive hydrocephalus.[ 2 ] Truncal ataxia and limb dysmetria may also occur in response to cerebellar involvement. Metastatic disease is frequent at diagnosis, especially in infants, occurring in around 30% of cases.

Since 1969, medulloblastoma risk stratification has undergone new modifications, and Chang’s original system is currently still in use.[ 1 ] Patients younger than 3 years old, with metastatic disease at diagnosis or with a residual tumor >1.5 cm², are considered high-risk patients. More recently, other features have been added to the original stratification: the presence of large cell/anaplasia or MYC amplification, both being part of the high-risk group, and Wnt subgroup as part of the low/average risk group.[ 5 ]

Survival rates in medulloblastoma patients improved toward the end of the 90s. Craniospinal radiotherapy as an adjuvant treatment reached overall cure rates of around 70%–85%. This led to a reduction in the risk of death by approximately 30%.[ 6 ] Nowadays, current treatment protocols include maximal safe tumor resection followed by radiotherapy in children older than 3 years old, and chemotherapy (CT) with cytotoxic agents, both according to risk stratification. For children under 3 years old, only CT with potent agents is allowed due to the possible damage caused by irradiation on an immature brain.[ 2 ]

In this article, we reviewed our 21 years’ experience in diagnosing and treating medulloblastomas at a children’s hospital, in Southern Brazil, dedicated to the public national health system. The aim of our study was to evaluate epidemiological data on medulloblastoma population, determining the spectrum and frequency of the variants encountered as well as if the data correlate with the current literature. The analysis of overall survival (OS) and event-free survival (EFS) rates in our cohort will enable us to check our institution treatment results and to compare to scientific literature data. The secondary objective is the identification of prognostic factors for survival among the analyzed variables.

PATIENTS AND METHODS

We retrospectively analyzed patients presenting histological medulloblastoma diagnosis from the tumor registry data bank of Santo Antonio Children`s Hospital. Among 423 children operated on for brain tumors, we identified 69 patients with medulloblastoma, diagnosed and treated between January 1995 and June 2016; all were operated by the same surgeon (JWJB). Only those with complete medical records and follow-up were included. Exclusion criteria were supratentorial primitive neuroectodermal tumors (PNETs) and insufficient clinical data and follow-up information.

The present study was approved by the hospital’s Research Ethics Committee in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments, under registration number CAAE 40232214.5.0000.5327.

Patient data were collected only from patients records on the following variables: age, sex, symptoms, prediagnostic symptomatic interval (PDSI), presence of hydrocephalus, tumor location, surgical approach, surgical resection, need of definitive hydrocephalus treatment, tumor histology, metastatic disease, tumor relapse, postoperative complication, and late sequelae.

Patient risk stratification was defined according to Chang’s system.[ 1 ] From 1995 to 2002, the stratification risk was based on transoperative impression and postoperative head and spine CT. Only after 2002, magnetic resonance imaging (MRI) scan became available. The extent of resection was divided, for the purpose of data analysis, in total resection, where patients who underwent gross total and near- total resection were included, subtotal and biopsy groups.

Adjuvant conventional radiotherapy was performed according to current protocols so that high-risk patients received craniospinal irradiation of 36 Gy and a posterior fossa boost to complete 54 Gy. Standard risk patients instead received 24 Gy to the neuroaxis in addition to a posterior fossa boost to complete 54 Gy. CT standard protocol consisted of eight doses, once a week, of vincristine in a dose of 1.5 mg/m² during radiation therapy (RT). Subsequently, eight cycles of vincristine in a dose of 1.5 mg/m², 75 mg/m² of cisplatin, and also 75 mg/m² of lomustine were administered. A variation of this protocol was also used, with cyclophosphamide instead of lomustine, and in certain cases, etoposide was associated with these two described protocols. High-risk patients received a high- risk protocol known as head start, with high doses of methotrexate, vincristine, etoposide, cisplatin, and cyclophosphamide in five cycles followed by autologous stem cell rescue.[ 3 ]

The statistical analysis was performed with IBM SPSS^® Statistics version 2.1. Quantitative variables were described by mean and standard deviation and interquartile range, depending on the distribution of data. Categorical variables were described by absolute and relative frequencies. OS and EFS were estimated with the Kaplan–Meier method. For OS, time was defined as the interval from the date of surgery to the date of death for all causes, with censoring at the date of the latest follow-up visit for live patients. For EFS, time was the interval also from the date of surgery to the date of an event such as relapse or death, with censoring at the latest follow-up visit for live patients and progression-free patients. For the prognostic effect of the variables, multivariate Cox regression analysis was applied. The criteria for entry of the variables into the multivariate model was that they had P < 0.20 value in the bivariate analysis and/or being relevant according to literature. The statistical significance level adopted was 5%.

RESULTS

Among the 69 patients enrolled from January 1995 to June 2016, only 61 patients had complete information in medical records, though two were excluded because they were not confirmed as medulloblastomas. From the 59 patients, 36 were male and 23 were female, a rate of 1.5:1.0. The mean age in this cohort was 6 years old, ranging from 5 months to 13 years old. Table 1 shows the sample clinical features in means and standard deviation or medium and interquartile interval.

Table 1

Clinical features.

All patients underwent surgery, with gross total resection achieved of 76.8%. The patient who only underwent a biopsy had M4 stage metastatic disease diagnosed at clinical presentation, with lung impairment. A second surgery was necessary for 17 patients due to local relapse or as a second-look surgery due to residual disease.

There were neither intraoperative nor surgical mortalities, considering this as death occurring within 30 days after the surgical procedure. Postoperative complications such as cerebrospinal fluid (CSF) leakage happened in only five cases. CSF increased cellularity was seen in 15 cases, and despite negative cultures, all of them were treated as meningitis. Posterior fossa syndrome was diagnosed in five (8.5%) patients. Tumor relapse occurred in 20 (34%) patients, in a mean time of 17 months, ranging from 5.5 to 39 months.

The 5-year OS and EFS were 44.5% and 36.4%, respectively, after a median follow-up time of 29 months, with an interquartile range of 10–79. The EFS and OS rates from this cohort according to the variables are shown in Figure 1 .

Figure 1

(a) Overall survival in 5 years of 44.5% and 10 years of 37.3%. (b) Event-free survival in 5 years of 36.4% and 10 years of 30.8%.

Long-term survival according to treatment protocols

The impact of surgical resection, radiotherapy, and CT protocols on OS and EFS is shown in the Kaplan–Meier curves in Figures 2 and 3 . CT protocols had no statistical significance among them. Although both adjuvant treatments had a positive impact on OS and EFS in bivariate analysis, only RT was significant when multivariate analysis was applied (OS p_adjusted = 0.003 and EFS p_adjusted = 0.005).

Figure 2

(a and b) Overall survival and event-free survival for radiotherapy.

Figure 3

(a and b) Overall survival and event-free survival for gross total resection.

Of the total number of patients who underwent CT, 15 had the protocol interrupted due to treatment complications (n = 1), death due to therapy complications (n = 6), or death due to disease progression (n = 8). All patients who underwent RT completed the protocol.

Multivariable analysis of clinical risk factors

Neither age, PDSI, need of hydrocephalus definitive treatment, nor tumor relapse had a prognostic impact. Postoperative complications were statistically significant on bivariate analysis, although multivariate analysis suggested the opposite (p_adjusted = 0.415). Metastatic disease at diagnosis was the only variable identified in this cohort that had significance (P = 0.022, HR 2.76; IC 1.16–6.58). Histology was not assessed in this cohort due to lack of information on histological subclassification and central pathology review. Only seven tumor specimens were categorized according to the WHO histological subclassification. Tables 2 and 3 describe Cox regression for OS and EFS and the variables used in this analysis.

Table 2

Overall survival – Cox regression analysis.

Table 3

Event free survival – Cox regression analysis.

DISCUSSION

During the 90s, OS in medulloblastomas improved with the inclusion of routine craniospinal radiation and CT protocols. At that time, several multicentric trials assessing treatment results on medulloblastoma began and are still in progress. The evaluation of the described OS and EFS can achieve rates as high as 90% in some trials.[ 9 , 17 , 24 ] Table 4 lists the trials and OS/EFS results.[ 7 , 11 , 18 , 23 , 24 ]

Table 4

Medulloblastoma trials.

Most publications on medulloblastoma patients’ survival describe the results of clinical trials, which have stringent eligibility criteria that necessarily influence the survival data.[ 19 ] Therefore, they may not be representative of the general population.[ 25 ] Most papers analyze children older than 3 years old and with no evidence of metastatic disease at diagnosis, two clinical data point that was previously recognized as a prognostic factor in other series.[ 13 ]

In regard to epidemiological data, population-based studies are more reliable. Weil et al., analyzing the SEER data (Surveillance, Epidemiology, and End Results Program – a central cancer registry of the U.S.), identified the year of 1990 as a critical time-point. They labeled two cohorts, the historic one (1973–1989) and the contemporary one (1990–2012), and compared their 5-year OS. They observed that OS ranged from 51% to 69% among both, thus being statistically significant (P < 0.001).[ 25 ] Johnston et al. also described this 5-year OS uplift, from 60% to 73%, in their cohort in Canada. For both authors, medulloblastoma incidence remained stable.[ 8 ] The probable cause of this improvement in outcome is unclear, though one should consider a number of points: better access to health care, faster initial diagnosis, greater recruitment into clinical trials, alternatives of adjuvant therapy, aggressiveness of management initially and at relapse, and better supportive care and improvement in RT and imaging technology.

The 5-year OS and EFS rates gathered from this cohort analysis were lower than those in the current scientific literature, despite the fact the extent of resection was 76.8% in accordance with the data reported in literature.[ 2 , 16 ] Undoubtedly, three factors might have influenced the findings: (1) the acquisition of the MRI by the studied institution happened in 2002, (2) there were numerous pediatric oncology teams performing in the same institution, and (3) the three-dimensional radiotherapy planning began to be implemented in 2005. Furthermore, it is proper to assume that the gross total resection rate could have been improved provided the use of a better quality microscope and ultrasonic aspirator. Taken together, these may be classified as everyday dilemmas in public health systems to economically developing countries.

The average time interval between symptom onset and diagnosis in our review has a median time of 30 days, in accordance with current data. Reulecke et al. reported an interval of 24 days in a German center, while Dobrovoljac et al. reported a higher interval of 60 days.[ 4 , 20 ] According to Kukal et al., who compared PDSI to patient’s age, tumor histology, tumor location, and OS, an association was found between tumor histology and location, though there was no correlation between PDSI and outcome in their series. Higher-grade tumors tend to have a smaller PDSI than lower-grade tumors, which may explain their finding.[ 10 ]

In contrast, our series comprises patients at high-risk stratification, including those younger than 3 years old. We also observed that among patients under CT protocols (n = 53), 15 had treatment interruption due to medical complications or death, meaning a loss of 30%. Von Hoff et al. reported that 70% of the patients under Packer CT protocol in the HIT91 cohort needed CT dose reduction due to toxicity, though all of them completed at least four cycles. Their analysis did not find any negative influence on survival rates.[ 24 ] Furthermore, patients who were submitted to the headstart protocol had a tendency to worse prognosis (EFS P = 0.007) which was not confirmed in multivariate analysis (P = 0.954). Overall, we did not find any difference between CT protocols, nor that CT in our series was a prognostic factor.

When we analyzed data according to stratification risk, the achieved rates in our cohort were more similar to other population-based studies. Fairley et al. found an OS of 54% in 5 years for children under 14 years old in the U.K.[ 6 ] Similarly, Smoll, in 2012, calculating the cumulative relative survival estimate, found a 5-year OS and 10-year OS of 25%/25% and 56%/52% for infants and children, respectively.[ 22 ] The lack of information from Brazilian cohorts does not allow internal comparisons.

Focusing on children younger than 3 years old, we observed an OS rate in 5 and 10 years of 45.9%. None of them underwent radiotherapy protocols, receiving only high dose CT. Rutkowski et al., in a meta-analysis evaluating survival and prognostic factors in children under 5 years old, found OS in 8 years of 56%. Prognostic factors included the extent of resection, metastatic stage, and the presence of desmoplasia/extensive nodularity and anaplasia/large cell tumor in histology.[ 21 ] Johnston et al. analyzed 96 children under 5 years old treated in Canadian pediatric oncology centers between 1990 and 2005. In this population- based study, the 5-year OS rate was 45.7%; however, 20% of their population was treated with CNS irradiation. As prognostic factors, radiotherapy and CT were statistically significant in their evaluation.[ 8 ]

In our analysis, we did not prove that younger children had a worse prognosis. On the contrary, our 5-year survival rates are similar in both groups (P = 0.92). Comparing our 5-year and 10-year OS, as well as EFS rates, especially in the youngest population, we observed minimal differences between them. Our case losses, therefore, occurred mostly before the 5-year follow- up period. As for the death in our cohort, we found that only one happened 6 years after the diagnosis. Another series found that 8 years following the initial diagnosis is a critical time point after which the odds of mortality from medulloblastoma are much lower when compared to all other-cause mortality.[ 25 ]

We achieved gross total resection in 76.8% of the children in our series. This number is in accordance with the current scientific literature.[ 2 , 16 ] Twelve children underwent subtotal resection and one had just a biopsy. Multivariate analysis showed that these two groups have a 177% greater chance of dying from medulloblastoma than those who had a total resection (P = 0.024). Gajjar et al. did not find an advantage in gross total resection in their series, nor an association between the extent of resection and the occurrence of posterior fossa syndrome.[ 7 ] Taylor et al. in the PNET 3 study also did not find this association.[ 15 - 23 ] Nonetheless, there are articles that do correlate the extent of resection with a better outcome.[ 26 ]

Curiously, hydrocephalus definitive treatment and postoperative complications were correlated to worse outcome in bivariate analysis. Shunt placement or endoscopic third ventriculostomy was needed in almost 50% of patients and those had a 188% greater chance of dying from the tumor. However, on multivariate analysis, it was not statistically significant for OS (P = 0.188). This might be related to the clinical presentation, but further studies are necessary.

There are several limitations to this study. It was not possible to perform both central pathological and radiological reviews due to the lack of access to the paraffin-embedded tissue blocks, as well as to the neuroaxis exams pre-MRI era. Furthermore, metastatic stage analysis was not possible due to the small number of patients in M2/M3 groups, as well as bias from false negative neuroimaging exams from the preMRI era and incomplete information from CSF sample acquisition. Finally, this study is subject to all the potential biases of a retrospective cohort.

CONCLUSION

As far as we know, this retrospective cohort is the largest one in Brazil that has evaluated medulloblastoma treatment outcome. Available information in literature is commonly derived from multicenter clinical randomized trials that include several countries, and sample sizes can reach hundreds of patients. Despite a limited sample, we were able to analyze OS and EFS rates in our institution, a typical public health system hospital in Brazil. The results that we have found are similar to population-based studies from the past two decades. Nevertheless, one should consider that working in a developing country, not rarely we face more difficulties in promoting the more appropriate treatment for medulloblastomas patients.

Similarly to other series, we found prognostic factors to be the extent of resection, the presence of metastatic disease, and posterior fossa and craniospinal irradiation. On the other hand, children younger than 3 years old were not correlated to a worse prognosis.

Finally, the study of this cohort of medulloblastoma epidemiological data provides the main features of this significant pathology in Southern Brazil, and we soon hope to be able to perform the molecular classification, which will provide the best treatment advances for our patients.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Chang CH, Housepian EM, Herbert C. An operative staging system and a megavoltage radiotherapeutic technic for cerebellar medulloblastomas. Radiology. 1969. 93: 1351-9

2. Chern JJ, Rao G, Lang FF, Winn R.editors. Medulloblastoma. Youmans Neurological Surgery. Philadelphia, PA: Elsevier Health Sciences; 2011. p.

3. Dhall G, Grodman H, Ji L, Sands S, Gardner S, Dunkel IJ. Outcome of children less than three years old at diagnosis with non-metastatic medulloblastoma treated with chemotherapy on the‘‘head start’’ I and II protocols. Pediatr Blood Cancer. 2008. 50: 1169-75

4. Dobrovoljac M, Hengartner H, Boltshauser E, Grotzer MA. Delay in the diagnosis of paediatric brain tumours. Eur J Pediatr. 2002. 161: 663-7

5. Ellison DW, Kocak M, Dalton J, Megahed H, Lusher ME, Ryan SL. Definition of disease-risk stratification groups in childhood medulloblastoma using combined clinical, pathologic, and molecular variables. J Clin Oncol. 2011. 29: 1400-7

6. Fairley L, Picton SV, McNally RJ, Bailey S, McCabe MG, Feltbower RG. Incidence and survival of children and young people with central nervous system embryonal tumours in the North of England, 1990-2013. Eur J Cancer. 2016. 61: 36-43

7. Gajjar A, Chintagumpala M, Ashley D, Kellie S, Kun LE, Merchant TE. Risk-adapted craniospinal radiotherapy followed by high-dose chemotherapy and stem-cell rescue in children with newly diagnosed medulloblastoma (St jude medulloblastoma-96): Long-term results from a prospective, multicentre trial. Lancet Oncol. 2006. 7: 813-20

8. Johnston DL, Keene D, Kostova M, Strother D, Lafay-Cousin L, Fryer C. Incidence of medulloblastoma in Canadian children. J Neurooncol. 2014. 120: 575-9

9. Kortmann RD, Kühl J, Timmermann B, Mittler U, Urban C, Budach V. Postoperative neoadjuvant chemotherapy before radiotherapy as compared to immediate radiotherapy followed by maintenance chemotherapy in the treatment of medulloblastoma in childhood: Results of the German prospective randomized trial HIT ‘91. Int J Radiat Oncol Biol Phys. 2000. 46: 269-79

10. Kukal K, Dobrovoljac M, Boltshauser E, Ammann RA, Grotzer MA. Does diagnostic delay result in decreased survival in paediatric brain tumours. ? Eur J Pediatr. 2009. 168: 303-10

11. Lannering B, Rutkowski S, Doz F, Pizer B, Gustafsson G, Navajas A. Hyperfractionated versus conventional radiotherapy followed by chemotherapy in standard-risk medulloblastoma: Results from the randomized multicenter HIT-SIOP PNET 4 trial. J Clin Oncol. 2012. 30: 3187-93

12. Louis DN, Ohgaki H, Wiestler OD, Cavenee WK.editorsWHO Classification of Tumors of the Central Nervous System. Lyon: International Agency for Research on Cancer; 2007. p.

13. Massimino M, Biassoni V, Gandola L, Garrè ML, Gatta G, Giangaspero F. Childhood medulloblastoma. Crit Rev Oncol Hematol. 2016. 105: 35-51

14. McKean-Cowdin R, Razavi P, Barrington-Trimis J, Baldwin RT, Asgharzadeh S, Cockburn M. Trends in childhood brain tumor incidence, 1973-2009. J Neurooncol. 2013. 115: 153-60

15. Packer RJ, Cogen P, Vezina G, Rorke LB. Medulloblastoma: Clinical and biologic aspects. Neuro Oncol. 1999. 1: 232-50

16. Packer RJ, Macdonald T, Vezina G, Grisold W, Soffietti R.editors. Medulloblastoma and primitive neuroectodermal tumors. Handbook of Clinical Neurology. Philadelphia, PA: Elsevier; 2012. p. 529-48

17. Packer RJ, Sutton LN, Goldwein JW, Perilongo G, Bunin G, Ryan J. Improved survival with the use of adjuvant chemotherapy in the treatment of medulloblastoma. J Neurosurg. 1991. 74: 433-40

18. Packer RJ, Zhou T, Holmes E, Vezina G, Gajjar A. Survival and secondary tumors in children with medulloblastoma receiving radiotherapy and adjuvant chemotherapy: Results of children’s oncology group trial A9961. Neuro Oncol. 2013. 15: 97-103

19. Pinho RS, Andreoni S, Silva NS, Cappellano AM, Masruha MR, Cavalheiro S. Pediatric central nervous system tumors: A single-center experience from 1989 to 2009. J Pediatr Hematol Oncol. 2011. 33: 605-9

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Abstract

Background: The aim of this paper is to provide a depiction of the surgical technique and dynamic story behind the procedures in pediatric neurosurgery.

Methods: Five standard common pediatric neurosurgeries: endoscopic third ventriculostomy, fronto-orbital advancement for metopic and coronal craniosynostoses, posterior fossa craniotomy, strip craniectomy for sagittal craniosynostosis, and ventriculoperitoneal shunting were chosen to be exampled in illustrations.

Results: Surgical techniques were depicted in a step-by-step fashion with comic-like style of images. Illustrations enable to highlight specific surgical and anatomical features and also convey surgical procedures in a sequential order from beginning to end as if it is a story.

Conclusion: Surgical illustrations may serve as an educational tool with potentially instructional value for practical application, especially for surgical trainees.

Keywords: Depiction, Neurosurgery, Pediatric, Surgical illustrations

INTRODUCTION

Technology has changed the nature of documentation in medicine. However, despite the realistic quality of photos and videos, illustrations remain a leading position in medical education.[ 1 , 3 ] From the beginning of medical history, illustrations were used as a tool to promote ideas from one physician to another.[ 2 , 4 ] The aim of this paper was to emphasize the surgical technique from beginning to end with multiple illustrations. With our ambition to address the complexity of these surgeries, we also embodied the comic-like feature and aspired to create simplicity of this nature.

We selected five common procedures of pediatric neurosurgery, in a series of positioning, surgical intervention, and subintervention [ Figures 1 - 5 ]. These procedures are examples that show how surgical illustrations can depict the dynamic story, as well as focus on specific surgical nuances. For each operation, we dissected the chronological train of intraoperative sequences to depict from beginning to end flow of surgery. We decided to use comic-like style of depiction to show dynamic story and step-by-step technique, to appreciate techniques with clear details.

Figure 1:

Ventriculoperitoneal shunting.

Figure 2:

Fronto-orbital advancement for metopic and coronal craniosynostoses.

Figure 3:

Strip craniectomy for sagittal craniosynostosis.

Figure 4:

Endoscopic third ventriculostomy.

Figure 5:

Posterior fossa craniotomy.

In our illustrations, we show one of many ways to perform common pediatric neurosurgical procedures. As the famous Latin proverb says “All roads lead to Rome,” procedures might be done differently but with the same result.

For example, there are several ways to perform a ventriculoperitoneal shunt. As neither anterior or posterior approach for insertion of ventricular catheter has shown significant superiority compare to each other. In most cases, we favor the posterior approach as it requires only two incisions instead of three in the anterior approach. Similarly, to save time and to achieve a better cosmetic result, we prefer insertion of the peritoneal catheter using trocar to minilaparotomy. In our experience, perforation of abdominal organs or missing abdominal cavity by trocar is extremely rare.

A ROOM FOR IMPROVEMENT

Max Brödel was the pioneer who famously created the original angle.[ 13 ] In his collaboration with Harvey Cushing for the depiction of transsphenoidal approach, Brödel deliberately depicted the patient in sagittal section to illustrate the heart of this surgery.[ 17 ] His legacy had carved the path and inspired countless innate artists like Cushing,[ 5 , 6 ] who exceptionally excelled at utilizing his artistic skills as a tool for surgical documentation, such as his pediatric cases.[ 12 , 14 ] Their imagination had set a milestone for medical education in neurosurgery, and we have not stopped improving since.

The notably mentioned Rhoton’s collection has a special place in modern academic neurosurgery.[ 15 ] From vibrant drawings to the actual dissection of cadavers, Rhoton’s careful selection of colors attracts newly scholars, professional neurosurgeons, and many others who are just curious about brain anatomy.

Another outstanding example of neurosurgical drawing collection is “Operative Neurosurgery” by Kempe.[ 8 ] He masterly depicted a beautiful perspective that neurosurgeon encounters during different neurosurgical operations. Furthermore, he was able to show critical steps each of operations and the way how neurosurgeon handles with different surgical maneuvers.

In the world of anatomical and surgical illustrations, it is impossible not to mention the legendary works of Frank Henry Netter. His atlases of normal anatomy and clinical subjects have become the most own for several generations of medical students and physicians.[ 1 , 7 ]

In more recent surgical perspective, Michael T. Lawton’s books comprise five different views: surgeon’s view, coronal view, other surgical view, real photo view, and imaging view. It has every viable detail which we need to know about the climax of that particular surgery.[ 9 - 11 ] In this digital age, many other free web-based multimedia, such as Juha Hernesneimi’s collection, are dedicated to provide learning material to show “how to do,” instead of “what to do” instruction.[ 3 , 4 ] These collections present mostly videos and drawings of the real operations, which only demonstrate the operative highlights, to keep the length of the videos and a number of pages to a minimum. In Shillito and Mantson’s book,[ 16 ] despite the static property in terms of visual sensation, illustrations could reflect a real flow of the procedure in one single page. For trainees and anyone who have only just begun their way in neurosurgery, small details such as the position of the endotracheal tube, lines of tapes, different supportive devices, and other equipment needed in the field have a special point of interest. While digitized images can undermine the patient’s confidentiality, illustration continues to be a guardian of a new production. Its transparency allows it to be publicized and may reach the larger scale of audiences, even outside medicine.

CONCLUSION

While digitized images can undermine the patient’s confidentiality, illustration continues to be a guardian of a new production. Its transparency allows it to be publicized and may reach the larger scale of audiences, even outside medicine.

Financial support and sponsorship

Dr. Rochanaroon has illustrated and presented this work as a poster and won the Best Student Poster Award at the 46th Annual Meeting of International Society for Pediatric Neurosurgery 2018 in Tel Aviv, Israel.

Conflicts of interest

There are no conflicts of interest.

References

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2. Cheng H, Chen BP, Soleas IM, Ferko NC, Cameron CG, Hinoul P. Prolonged operative duration increases risk of surgical site infections: A systematic review. Surg Infect (Larchmt). 2017. 18: 722-35

3. Choque-Velasquez J, Kozyrev DA, Colasanti R, Thiarawat P, Intarakhao P, Jahromi BR. The open access video collection project Hernesniemi’s 1001 and more microsurgical videos of neurosurgery: A legacy for educational purposes. Surg Neurol Int. 2017. 8: 188-

4. Davidson B, Alotaibi NM, Hendricks BK, Cohen-Gadol AA. Popularity of online multimedia educational resources in neurosurgery: Insights from the neurosurgical atlas project. J Surg Educ. 2018. 75: 1615-23

5. Elmaci I, Balak N. Pioneering turkish neurosurgeon hami dilek and the traces of harvey cushing’s legacy in his work. J Neurosurg. 2008. 108: 821-9

6. Groen RJ, Koehler PJ, Kloet A. The role of harvey cushing and walter dandy in the evolution of modern neurosurgery in the netherlands, illustrated by their correspondence. J Neurosurg. 2013. 118: 539-49

7. Jones HR, Netter FH.editors. Netter’s Neurology. Icon Learning Systems. 2005. p.

8. Kempe LG.editors. Operative Neurosurgery: Cranial, Cerebral, and Intracranial Vascular Disease. Vol. 1. New York: Springer Berlin Heidelberg; 1985. p.

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10. Lawton MT.editorsSeven AVMs: Tenets and Techniques for Resection. New York: Thieme; 2014. p.

11. Lawton MT.editorsSeven Bypasses: Tenets and Techniques for Revascularization. New York: Thieme; 2018. p.

12. Mehta VA, Wijesekera O, Pendleton C, Quiñones-Hinojosa A, Jallo GI, Ahn ES. Harvey cushing and “birth hemorrhage”: Early pediatric neurosurgery at the johns hopkins hospital. J Neurosurg Pediatr. 2011. 8: 647-53

13. Patel SK, Couldwell WT, Liu JK. Max brödel: His art, legacy, and contributions to neurosurgery through medical illustration. J Neurosurg. 2011. 115: 182-90

14. Pendleton C, Ahn ES, Quiñones-Hinojosa A. Harvey cushing and pediatric brain tumors at johns hopkins: The early stages of development. J Neurosurg Pediatr. 2011. 7: 575-88

15. Peris-Celda M, Martinez-Soriano F, Rhoton AL.editorsRhoton’s Atlas of Head, Neck, and Brain: 2D and 3D Images. New York: Thieme; 2017. p.

16. Shillito J, Matson DD, Codding MB, Lashbrook GS.editorsAn Atlas of Pediatric Neurosurgical Operations. Philadelphia, PA: W.B. Saunders Co.; 1982. p.

17. Udelsman R. Presidential address: Harvey cushing: The artist. Surgery. 2006. 140: 841-6