Tumor origin and hearing preservation in vestibular schwannoma surgery.

OBJECT: Preservation of cochlear nerve function in vestibular schwannoma (VS) removal is usually dependent on tumor size and preoperative hearing status. Tumor origin as an independent factor has not been systematically investigated.

METHODS: A series of 90 patients with VSs, who underwent surgery via a suboccipitolateral route, was evaluated with respect to cochlear nerve function, tumor size, radiological findings, and intraoperatively confirmed tumor origin. All patients were reevaluated 12 months after surgery.

RESULTS: Despite comparable preoperative cochlear nerve status and larger tumor sizes, hearing preservation was achieved in 42% of patients with tumor originating from the superior vestibular nerve, compared with 16% of those with tumor originating from the inferior vestibular nerve.

CONCLUSIONS: Tumor origin is an important prognostic factor for cochlear nerve preservation in VS surgery.