Facial nerve function and hearing preservation acoustic tumor surgery: does the approach matter?

Objective: The retrosigmoid and middle fossa approaches to acoustic tumor excision allow for hearing preservation but differ in the angle of approach to the facial nerve. The authors comparatively examined facial nerve results of each approach.

Study Design: Case series with chart review.

Setting: Multiple physician subspecialty practice.

Subjects And Methods: The authors reviewed facial nerve outcomes of patients undergoing acoustic tumor excision at a single subspecialty practice that had used a hearing preservation approach for the past 15 years. The retrosigmoid and middle fossa approaches were compared. Hearing results and recurrence rates were also examined.

Results: One hundred thirty-eight patients had adequate data for inclusion in this study. Of the patients undergoing a middle fossa approach, 80 percent had a House-Brackmann (HB) grade I-II outcome, whereas 90 percent of patients undergoing the retrosigmoid approach had an HB grade I-II. When classifying HB I and II outcomes together, we did not find a statistically different result between the surgical groups. Upon more critical analysis, however, facial function recovered faster and there were more long-term HB grade I function results in the retrosigmoid group. There were more recurrent/residual tumors in the retrosigmoid group and better hearing preservation in the middle fossa group.

Conclusion: There are small but important functional outcome differences between the retrosigmoid and middle fossa approach for acoustic tumors. The clinician needs a working understanding of these differences so that the correct approach can be used to produce the best results for each patient.