Hearing preservation--posterior fossa approach.

In patients with acoustic neurinomas protruding less than 2 cm from the porus acusticus and free of the brain stem, hearing can often be preserved. Our neurosurgical/otologic team uses the combined suboccipital/transmeatal approach with the patient in the seated position. This operation has been attempted on 21 patients from 1974 to 1982. Nine had tumors larger than 2 cm that touched the brain stem; one had useful hearing preserved. Of the 12 patients with tumors smaller than 2 cm, hearing at or near the preoperative level was preserved in seven. In one patient, hearing was improved. There have been up to 7 years of follow-up with no recurrences of the neurinomas or diminution of hearing evident on computed tomographic scan. All had preservation of the seventh cranial nerve, while complications were mild and comparable to the remainder of our 101 patients operated on during the same period. We will review the surgical technique and audiologic results in detail.