Microsurgical removal of large meningiomas involving the clivus

Objective To review the radiological features, operative approaches, microsurgical technique and results in cases of involving clival meningiomas, for rise the total removal rate, lower operative mortality and morbidity and improve operative results.Methods A series of 34 patients harbouring clival meningiomas which were operated on between 1988 and 1997 were analyzed retrospectively. The following approaches were used: (1) orbitozygomatic temporopolar approach in 9 cases; (2) frontotemporaltranscavernous approach in 2 cases; (3) transpetrosal and tentorial approach in 13 cases; (4) suboccipital retromastoid approach in 6 cases; (5) extreme lateral transcondylar approach in 3 cases; (6) transoral transpharyngeal approoach in 1 case. Results Good postoperative results were got in 29 patients(85%). Total excision documented by postoperative CT scans was in 19 patients(56%). Operative death was in 1 patient(2%). Postoperatively, new cranial nerve deficits occurred in 16 patients(47%), of which there was permanent worsening of function of cranial nerve in 4 cases(12%). Intraoperative technical difficulties, which may affect outcome, included tumor consistency, vascularity, lossing the arachnoidal plane of dissection from the brain stem, and vascular and cranial nerve encasement. Conclusion The development and refinements of new cranial base approaches and microsurgical technique have risen total removal rate, with low attendant mortality and acceptable morbidity. Because the most important goal of surgical resection is a good postoperative result, subtotal removal of tumor and residual tumor with gamma knife therapy should be considered when the tumor is large or without arachnoidal dissecting plane.