Preservation of hearing in bilateral acoustic neurinomas by deliberate partial resection.

With the aim of preserving hearing, 20 acoustic neurinomas in 17 patients with neurofibromatosis 2 were intentionally submitted to an incomplete (80%) tumour removal. In 12 cases this was an operation on the last hearing ear with total deafness of the contralateral ear. If an auditus existed in both ears the better hearing ear was selected for the primary intervention. Early audiological controls evidenced residual hearing in 19 of the 20 cases operated on by the enlarged middle fossa approach, which was utilized inspite of the tumour diameters being between 1 and 6 cm in the cerebello-pontine angle. The oncologic and functional follow-up over 1 to 7 years showed different patterns of slow progression of hearing loss and of persistent auditory function over 2 to 7 years. Facial nerve function was excellent in 16 of the 18 controlled cases. Continued CT or MRT imaging revealed no signaling in 2 cases, constant tumour sizes in 10 cases and slow progression in 3 cases. With regard to the importance of an auditory communication in the younger adult, the described treatment modality appears to be the first choice method.