Retromastoid microsurgical approach to vascular compression of the eighth cranial nerve.

In our series of 10 patients, the age ranged between 31 and 69 years. Seven patients were followed for from 1-2 1/2 years. Complaints consisted of tinnitus, vertigo, or both. Vegatative symptoms consisting of nausea or vomiting were minimal or absent. Audiometry revealed a varying neurosensory loss. Vestibular hypoexcitability was a common finding. Good discrimination appeared to indicate a vascular loop rather than hydrops. The neuroradiological work-up was unremarkable. Treatment consisted of neurovascular decompression of the VIIth nerve by microdissection. The approach used was a retromastoid incision with a bony removal limited to 20 mm. Cerebrospinal fluid withdrawal and lateral decubitus positioning permitted visualization of the VIIIth nerve without retraction of the cerebellum. Lack of bleeding, rapidity of procedure and benign postoperative course are emphasized. The results on tinnitus and vertigo were satisfactory. No additional deficit was created by surgery. If the symptoms are significantly disabling, microsurgical exploration is indicated.