Anterior Skull Base Meningiomas. Surgical Series of 70 Cases

Purpose: To report clinical presentation, surgical procedures, grade of resection, and postoperative course in a surgical series of anterior skull base meningiomas.

Method and Result: Among 160 consecutive patients who underwent surgery for skull base meningioma, we selected 70 meningiomas arising from the anterior base: olfactory groove (21 cases); planum sphenoidale-tuberculum sellae (23); anterior clinoid (17); and orbital roof and mixed origin (9). Symptoms and signs were correlated to tumor location. Total meningioma removal (Simpson I and II) was achieved in 58 cases (83%); in 12 (17%) partial removal was done because of encasement of the carotid artery, cavernous sinus, or optic nerves. Postoperative outcome: excellent or good results (complete recovery or moderate disability) in 63 cases (90%); poor outcome (severe disability) in 1 case; death in 6 cases (8%). Tumor recurred in 4 patients (6%). The extent of resection and results were closely related to the meningiomas' site. In the olfactory groove, all patients underwent a pterional approach and complete excision. There was excellent postoperative outcome in 19 patients; 2, with poor preoperative conditions, died after surgery because of extraneurological complications. No tumor recurred in survivors. In the planum sphenoidale-tuberculum sellae group, all patients received the pterional approach. There was complete removal in 17; 6 had partial excision because of neurovascular structural involvement. In 22 patients the postoperative course was uneventful. There was only 1 death. One patient, with tuberculum sellae meningioma regrowth 4 years after the surgery, was operated again successfully. In the anterior clinoid cases, all patients underwent the pterional approach. There was total removal only in 65% of cases since in a high percentage an incomplete excision was thought obligatory because of the close relationship of meningiomas with the surrounding neurovascular structures. Postoperatively, 13 patients showed satisfactory outcome, 1 presented with severe morbidity, and 3 died. Three patients experienced regrowth. In the remaining locations (orbital roof and mixed origin), complete resection was done through the surgical approach chosen according to the meningiomas' site; the operative results were completely positive.

Conclusion: The site of meningiomas was extremely important regarding the amount of tumor resection and the postoperative outcome. The anterior clinoid location appeared to be an unfavorable prognostic factor; this is not surprising based on the published series. Considering the analysis of the reviewed literature, we believe that our overall results in the surgical treatment of anterior basal meningiomas can be considered satisfactory.