Tentorial meningiomas: surgical experience with 61 cases and long-term results.

The authors report their experience and long-term results in the surgical treatment of 61 tentorial meningiomas. These cases were operated on between 1951 and 1985 and represented 4.8% of all intracranial meningiomas operated on in that period. The mean duration of clinical history was 29 months, except for cases of meningioma of the posteromedial border, for which it was 5 years. Plain x-ray films and cerebral angiograms were obtained in all cases. Computerized tomography, performed in the last 20 cases (32.7%), supplied much better lesion topography and early diagnosis. The tumor site was posterolateral in 26 cases (42.6%), anterolateral in 14 (22.9%), posteromedial in eight (13.1%), at the free border in seven (11.4%), and in the tentorium itself in six (9.8%). Lateral and medial tumors with solely or mainly supratentorial development were approached from above. The approach from below was reserved for meningiomas with subtentorial involvement only. In meningiomas with both supra- and subtentorial growth, a supratentorial bone flap was combined with a suboccipital craniectomy using a retromastoid incision. The mortality rate was 9.8%. Of the remaining 42 patients, who were followed for at least 5 years, long-term results were good in 26 cases (61.9%), fair in 11 (26.2%), and poor in five (11.9%). Postoperative complications arose in 34% of the patients, but cleared in 27%.