[Tentorial meningioma. Surgical experience with 20 cases].

We report our experience and long-term results of twenty patients with tentorial meningiomas who underwent surgical removal between 1987 and 1996. Computed tomography, angiography and magnetic resonance imaging were used as diagnostic tools for planning the surgical procedure. The tumor site was posterolateral in 6 cases (30%), posteromedial in 4 cases (20%), in the tentorium itself in 4 cases (20%), anterolateral in 3 cases (15%), at the apex of tentorial incisura in 2 cases (10%) and at the free border of the tentorial notch in 1 case (5%). Neuroradiologically, 70% of the meningiomas ranged from 1 to 3 cm. Lateral and medial tumors with solely or mainly supratentorial development were approached from above. The approach from below was selected 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. Radical surgical removal (Simpson's grade I and II) was achieved in 80% of the cases. There was no mortality. The follow-up averaged 4 years and revealed that 65% of patients were able to return to their premorbid activity. Complications were mainly postoperative brain oedema, functional deficits, seizures and psychological disorders. Recurrence rate amounted at 6.25% in the group where the tumors were totally removed (16 cases). From this retrospective study, the statistically significant prediction of a good outcome was: duration of symptoms from onset to the operation inferior or equal to 1 year (p < 0.01), good preoperative neurological conditions (Karnofsky scale from 80 to 100) (p < 0.05) and tumor size inferior or equal to 3 cm (p < 0.002).