Anesthetic Management of Posterior Fossa Surgery in Children

Posterior fossa tumors are more common in children as compared to adults. The majority of brain tumors (54–70%) in the pediatric age group occur in the posterior fossa (15–20% in adults). The reason behind the propensity of these tumors to occur in the posterior fossa has not been elucidated to date. Posterior fossa lesions may be neoplastic, developmental, or vascular lesions amenable to surgical intervention. Chiari malformations occur as congenital defects when a portion of the skull base fails to grow large enough to accommodate the cerebellum that would result in brain tissue extending into the spinal canal. By far, the most common posterior fossa tumors of childhood are astrocytomas, medulloblastomas, ependymomas, and brainstem gliomas. Cerebellar astrocytomas, usually slow-growing and benign, are the most common (40–50%), followed by medulloblastomas (malignant) comprising (20–25%) of all pediatric brain tumors. Other less frequent tumors include atypical teratoid rhabdoid tumor, hemangioblastoma, dermoid, schwannoma, cerebellar gangliocytoma, meningioma, and metastatic tumors. The median age at diagnosis of posterior fossa tumors in children is approximately 6–9 years, with a peak incidence in the first decade of life. Most of the tumors occur in the midline and are frequently found associated with hydrocephalus. Success with surgical intervention has become possible because of improved understanding of physiology, advances in imaging and microsurgical techniques, excellent anesthetic techniques available, and advances in the child’s perioperative care. These, in turn, have improved the survival and quality of life in children.