Current surgical results of retrosigmoid approach in extralarge vestibularschwannomas

BACKGROUND Vestibular schwannomas (VS) are common tumors that can be cured; they are r eported to comprise 6 similar to 8% of all intracranial tumors. The primary objective in the surgery of extralarge VS is total removal of the tumor ma ss while preserving the facial nerve. In extralarge tumors, complete excisi on of the tumor carries a significant risk of injuring the facial nerve and adjacent vital brain structures. The authors are reporting the techniques and results of operation on extralarge VS. METHODS The material consisted of 30 patients during the last 6 years with surgical ly treated VS that had a maximal extrameatal diameter exceeding 4 cm. Suboc cipital craniotomy and tumor removal was performed with patients in the lat eral position. Results and complications of the surgical technique will be reviewed. RESULTS Average age of patients was 45.2 years; there was a slight female predomina nce (1.5:1). Size of the mass ranged from 41 to 70 mm; all were removed by the retrosigmoid transmeatal approach. Peritumoral edema on MRI was seen in 50% (15/30). Total removal was achieved in 73.3% (22/30) with no significa nt relationship to peritumoral edema. In the cases of total removal, the fa cial nerve preservation rate was 86.4% (19/22). There was no mortality. Sur gical complications were hemorrhage and CSF leakage id 1 case (3%) and 8 ca ses (26.7%), respectively, but in most of these cases, conservative treatme nt was adequate. In patients in whom anatomic preservation of the facial ne rve was achieved, facial nerve function improved progressively within a yea r. In all cases except for one with gait disturbance, a good outcome was ac hieved. CONCLUSIONS Our surgical techniques, including the prediction of facial nerve displacem ent, not using retractors, and replacement of bone, contributed to good sur gical results in a series of extralarge VS. (C) 2000 by Elsevier Science In c.