Analysis of Hearing Preservation and Facial Nerve Function for Patients Undergoing Vestibular Schwannoma Surgery: The Middle Cranial Fossa Approach versus the Retrosigmoid Approach – Personal Experience and Literature Review

Abstract

Objective: To compare hearing preservation and facial nerve function outcomes in patients undergoing vestibular schwannoma surgery performed using either the middle cranial fossa approach (MCFA) or the retrosigmoid approach (RSA). Materials and Methods: A review of the medical records of patients diagnosed with vestibular schwannoma who underwent surgical tumor removal in a single reference center via the MCFA or the RSA between January 1988 and December 2008 was conducted. Results: During this period, 90 patients underwent surgery via the MCFA while 86 patients received surgical treatment via the RSA. Of the patients subjected to the MCFA, 80.7% were characterized by a House-Brackmann (HB) grade I or II outcome, whereas 96.5% of patients undergoing the RSA were characterized by a HB grade I or II outcome (p = 0.001). This difference appeared only for extrameatal tumors when we compared size-matched tumors (58.3% MCFA vs. 98% RSA; p = 0.0006). There was no statistically significant difference in the hearing outcomes upon consideration of hearing preservation as characterized by the modified Sanna classification system involving classes A and B (18.9% MCFA vs. 10.6% RSA; p = 0.122). Conclusion: No statistically significant difference in hearing preservation was identified when comparing tumors operated upon via the MCFA versus the RSA. However, our results indicate that a higher risk of facial nerve function impairment exists if the surgery is performed via the MCFA under circumstances where the tumor extends to the cerebellopontine angle.