Surgical Management of Posterior Fossa Meningioma

Abstract

A series of 54 posterior fossa meningiomas treated from January 1971 to December 1996 is reported. The patients were 42 women and 12 men ranging in age from 35 to 83 years (mean 55.6 years). Grouped by the site of tumor attachment, these tumors were divided into six categories: tentorial, petroclival, cerebellopontine angle, falcotentorial, cerebellar convexity, and foramen magnum meningiomas. Surgical approaches were selected on the basis of the tumor attachment and extension, the involvement of major cerebral arteries and the venous system, and the involvement of the cranium and brain stem on preoperative neuroimaging. Of 54 patients, 50 underwent operation. Total removal (Simpson I, 8 cases; Simpson II, 27 cases) was achieved in 35 patients (70%), subtotal removal (Simpson III) in 5 patients (10%), and partial removal (Simpson IV) in 10 patients. Eight patients had immediate surgical complications, and the morbidity rate was 16%. One patient died; thus, the mortality rate was 2%. All patients were followed over a mean of 8.1 years (range 3 months to 22 years) after surgery. Recurrence occurred in three patients, two with tentorial meningioma and one with petroclival meningioma. With advances in neuroradiology and micro-surgical techniques, the surgical outcome of meningiomas has markedly improved. The present surgical approach, including skull base operative techniques and intraoperative monitoring and navigation, has resulted in successful removal of posterior fossa meningiomas more safely with acceptable mortality and morbidity rates.