Hearing preservation in acoustic neuroma surgery. Middle fossa versus suboccipital approach.

Over the past few years there have been reports discussing the preservation of hearing after the removal of acoustic neuromas through the middle cranial fossa or the suboccipital approaches. This is a complex issue with many facets and controversies. In an attempt to answer at least some of these controversies, this article reviews the experience of our group. Preservation of hearing was attempted in thirty-four cases out of 220 acoustic neuromas. In twenty cases the middle fossa approach was used: All tumors were less than 2 cm from the fundus, and in four patients the tumor was bilateral. In sixteen of the twenty (80%) the cochlear nerve was spared; in ten of twenty (50%) measurable hearing was retained, but in only four (20%) was the postoperative hearing serviceable according to the 50/50 rule. In fourteen cases the suboccipital approach was used: All but two of the tumors were smaller than 2 cm. In three patients the tumor was bilateral. The cochlear nerve was preserved in ten of the fourteen cases (71.4%). Measurable hearing was present in four of fourteen cases postoperatively (28.6%); none had serviceable hearing according to the 50/50 rule. Hearing was not preserved in any bilateral tumor case. The middle fossa and the suboccipital approaches are discussed as well as the relative merits of each procedure in preservation of hearing.