Acoustic neuroma surgery with emphasis on preservation of hearing.

A review is presented of 34 cerebellopontine angle tumors surgically removed between 1973 and 1978 by the author at the New York University Medical Center. A diagnostic protocol is outlined: An acoustic PEG (small volume pneumoencephalogram with polytomography) is utilized where a medium to large tumor is suspected, and a Pantopaque fossagram for the smaller tumors. Indications are given for the middle fossa, translabyrinthine and suboccipital approaches, depending on tumor size and level of hearing. Hearing was successfully preserved at or near the preoperative level in 3 of 6 extracanalicular tumors operated upon using the suboccipital microsurgical approach. Audiometric data are given, demonstrating the preservation of hearing. The surgical technique is described. There were no fatalities in the entire series. The incidence of permanent facial nerve palsy was 8%. Nerve palsy occurred in large tumors only.