Surgical approach to the posterior fossa in children, including anesthetic considerations and complications: The prone and the sitting position. Technical note.

INTRODUCTION: Medulloblastoma (MB) in children is, in most cases, a midline lesion located in the posterior fossa, with a high tendency to invade the fourth ventricle (and sometimes its floor). METHODS: In this technical note, we present both the sitting and the prone position for children with medulloblastoma. These positions will be described together by deliberately deciding not to oppose one against the other. The park bench position, seldom used in pediatric neurosurgery is not described here. The latter procedure can be useful, however, for MB located more laterally or within the cerebellopontine angle. RESULTS: The aim of this technical note is to provide the reader with a step by step procedure (from installation to closure), at least from the author's point of view. A special focus regarding anesthetic considerations is also provided. This anesthesia requires perfect coordination and communication between both the anesthetic and surgical teams. Complications of posterior fossa surgery are mentioned as well. Some of the advantages and disadvantages of each positions are mentioned. CONCLUSION: Only careful installation, respect of certain surgical principles (careful attention of the vermis and dentate nuclei for example), knowledge of anatomy, closure and perioperative monitoring, screening and immediate correction of potentially devastating complications will enable surgeons to obtain the best results from their surgery.

Spinal cord tumors in children: A review of 21 cases treated at the same institution.

INTRODUCTION: Spinal cord tumors in children (SCTC) are rare with a frequent diagnostic delay. Its management is multidisciplinary and challenging due to functional implications. The position of surgery is now better established but the role and timing of chemotherapy (CT) and radiotherapy (RT) still remains under debate. Adverse effects of treatments are important to be taken into account, in the follow-up of these children. The aim of this paper was to present a series of 21 cases of SCTC treated at the same institution, to briefly present clinical features, treatments and outcome, with a special focus on spinal deformities in children with this condition. MATERIAL AND METHODS: Twenty-one consecutive SCTC were referred to our institution from 1990 to 2014. Data regarding age, sex, diagnostic delay, clinical examination, MRI, surgery, pathology, other treatment (CT and RT), orthopedic issues and follow-up of these children were retrospectively recorded. RESULTS: Mean age was 8years (standard deviation: 5.2years) (range: 4 months-17years). Mean diagnosis delay was 5.5 months (standard deviation: 6.5 months) (range: 0 days-18 months). All children (10 girls, 11 boys) were operated on (10 partial removals, 7 subtotal and 4 gross total removals) as first-line treatment. Pathological results showed 12 juvenile pilocytic astrocytomas, 1 grade III astrocytoma, 1 grade IV astrocytoma, 3 oligodendrogliomas, 2 ependymomas, 1 glioblastoma and 1 rhabdoid tumor. Fourteen children (66.7%) received additional treatment: 12 CT and 7 RT. Ten children had postoperative spinal deformities. Mean follow-up (FU) was 71 months (5 months-180 months), with a median FU at 60 months, where 8 tumor progressions and 4 deaths were observed. Overall, survival (at 5years) was 81% and progression free survival (at 5years) was 67%. CONCLUSION: Surgery is the goal standard for SCTC and the only appropriate treatment in cases of a low-grade lesion with stable disease on MR follow-up. Additional treatment must be reserved for high-grade lesions or tumor progression not attainable by a second look surgery. Spinal deformities are a frequent complication. Overall, survival and event free survival primarily depends on the pathology. Studies involving more centers are obligatory with the aim of collecting more cases and drawing more definitive conclusions regarding the management of these tumors.