Hearing conservation in acoustic neuroma surgery via the posterior fossa.

An increasing number of patients with an acoustic neuroma present with useful hearing in the tumour ear. Surgical removal of these tumours via the posterior fossa route may enable preservation of the cochlear nerve and otic capsule without increasing the morbidity to the facial nerve. The results of treating 51 cases of acoustic neuroma via the posterior fossa is presented. Forty four tumours measured less than 20 mm in diameter in the cerebellopontine angle and surgery was undertaken with hearing preservation as a principle objective. In 26 cases, the cochlear nerve was preserved anatomically and post-operative hearing at levels better than mean pure tone threshold of 50 dB or 50 per cent speech discrimination was recorded in 14 patients. The preservation of hearing represents a worthwhile surgical goal in selected patients with an acoustic neuroma without increasing the operative morbidity.