Posterior fossa meningiomas: Surgical experience in 161 cases

BACKGROUND We report the clinical, radiological, and surgical findings of p atients with posterior fossa meningiomas surgically treated at our institut ion over the last 6 years. METHODS We reviewed 161 consecutive cases of posterior fossa meningiomas op erated on between April 1993 and April 1999 at The George Washington Univer sity Medical Center. RESULTS There were 128 female and 33 male patients (mean age 47 years, rang e of 10-81 years). Meningiomas were classified as petroclival (110 cases), foramen magnum (21 cases), cerebellar hemispheric, lateral tentorial (14 ca ses), cerebellopontine angle (9 cases), and jugular foramen (7 cases). Mean tumor equivalent diameter (TED) = (D1XD2XDE)(1/3) was 3.1 cm (range of 0.5 3-8.95). Head pain (50% of cases) and disturbance of gait (44%) were the mo st common presenting symptoms, and cranial neuropathies the most common neu rological signs on admission. Mean preoperative performance status (Karnofs ky scale) was 80.2 (range 40-100). Surgical approaches to these tumors incl uded partial labyrinthectomy petrous apicectomy, fronto-temporal/fronto-tem poral orbitozygomatic osteotomy, retrosiginoidal, extreme lateral, transpet rosal, and combined. In 38 cases a staged procedure was performed. Gross-to tal resection was achieved in 57% of patients, and subtotal/partial in 43%. Surgical mortality was 2.5% and complications were encountered in 41% of p atients. Postoperative CSF leak occurred in 22 cases (13.6%). The mean foll ow-up was 19 months, ranging from 0.2 to 63.6, and the mean performance sta tus of patients with a follow-up of at least 12 months was 77 (range of 40- 100). Recurrence or progression of disease was found in 13.7% of cases (fol low-up 2 years or more). CONCLUSION Our experience suggests that although posterior fossa meningioma s represent a continuing challenge for contemporary neurosurgeons, such tum ors may be completely or subtotally removed with low rate of mortality and acceptable morbidity, allowing most of these patients to achieve a good out come in a long-term follow-up. (C) 2001 by Elsevier Science Inc.