Fundus obliteration and facial nerve outcome in vestibular schwannoma surgery.

The major objectives in vestibular schwannoma (VS) surgery have evolved from reducing mortality to functional preservation of the facial nerve and hearing. Absence of fluid between the lateral end of the VS and the internal auditory canal fundus on magnetic resonance imaging (MRI) appeared to have a negative influence on hearing outcome. Our goal was to study the prognostic significance of fundus obliteration on facial nerve function after VS surgery in patients with clinically normal facial function. We performed a retrospective review in a tertiary referral neurotology unit or 110 consecutive patients with a surgically removed VS and normal preoperative facial nerve function. Facial nerve function was evaluated at 1 month and 1 year by using the House-Brackmann (HB) scale and correlated to fundus obliteration on MRI. Facial nerve function was intact preoperatively in 114 of 123 patients (92.7%). We noticed a statistically significant difference and worse short-term outcome when the fundus was obliterated: 29.7% had HB 3 or more versus 13.0% if no fundus obliteration was seen. This statistically significant difference disappeared at 1 year. Fundus obliteration has a negative prognostic influence on short-term facial nerve function after VS surgery in patients with clinically normal facial function preoperatively.