The technique, results, advantages, and complications of a combined translabyrinthine-transtentorial approach to the cerebellopontine angle are discussed. The method has been associated with a low morbidity and no operative mortality in 23 cases of acoustic nerve tumor and six with miscellaneous lesions. KEY WORDScerebellopontine angle tumors tentorial approach translabyrinthine transj. Neurosurg. / Vohane 38 / March, 1973

The translabyrinthine route or an extension of it was used to remove 150 acoustic nerve tumors. The mortality was 2% and the morbidity low. Preservation of the facial nerve was achieved in 100% of the small and 80% of the medium-sized tumors, but in only 20% of the large growths. The complications encountered are discussed.

A retrospective study of the surgical management of 41 cerebellopontine angle (CPA) meningiomas was performed. All patients were treated by a single surgeon (TTK) over a 25 year period (1967-1992). There were 13 males, 28 females with a median age of 53.5 years. The median follow-up after surgery was 9 years (range 2-20.4 years). Tumours were classified anatomically into six groups (lateral, midpetrosal, petroclival, internal auditory meatal, Meckel's cave and inferior). Only the petroclival tumours posed difficulties with complete resection (achieved in 7 out of 16) and for most of them a transtentorial transpetrous approach was used. In other groups, complete resection was achieved in all patients. There were four recurrences (two mid-petrosal, one petroclival, one internal auditory meatal), three of which had complete macroscopic resection at the initial operation.

The results of a U.K. study of 145 cases of type 2 neurofibromatosis has shown generally very poor operative results in terms of hearing and facial nerve preservation. Only 9 out of 118 vestibular schwannoma (acoustic neuroma) operations resulted in any clinically detectable hearing preservation and only 32 left the patient with good or normal (House grade I or II) ipsilateral facial nerve function. Although operation is still the definitive treatment of vestibular schwannoma (acoustic neuroma) and may be a lifesaving procedure, it appears that the evidence in favour of early operation is only valid when carried out in highly specialized centres. The special problems of NF2 cases who may go on to develop multiple spinal and cranial tumours making them wheelchair bound and blind as well as deaf warrants a careful experienced approach. Timing of operations may be critical for the enhancement of useful years of quality life. We therefore propose the setting up of a national NF2 register, with the management of cases at a few supraregional centres.

In a series of over 500 cases of cerebellopontine angle tumors, 19 patients had bilateral neurinomas. Four of these tumors arose from the facial rather than the acoustic nerve. A conservative policy regarding surgery had been adopted in an effort to prevent hearing loss for as long as possible. Nevertheless, all patients operated on in this series are now totally deaf. The results of managing these patients surgically and conservatively are discussed.