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Updated: Sep 30, 2026
In Vivo Morphometric Analysis of Human Cranial Nerves Using Magnetic Resonance Imaging in Menière's Disease Ears and Normal Hearing Ears
Published on: February 21, 2018
Risk-benefit analysis of using the middle fossa approach for acoustic neuromas with >10 mm cerebellopontine angle
Bulent Satar1, Robert K Jackler, John Oghalai
1Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California 94143-0342, USA.
Objectives:
To evaluate hearing preservation and facial nerve (FN) outcome in the middle fossa (MF) approach for acoustic neuromas with a cerebellopontine angle (CPA) component >10 mm.
Study Design:
Retrospective review of 193 patients.
Patient Population:
Patients were grouped according to tumor size: intracanalicular tumors (IC; 64), 1 to 9 mm CPA extension (42), and 10 to 18 mm CPA extension (47). Additionally, a group of 40 patients (tumor size 10-18 mm CPA extension) who had undergone a translabyrinthine (TL) approach was studied to assess comparative FN outcome. Hearing and FN function were measured 1 year postoperatively. We defined the success at functional hearing preservation as AAO-HNS class B or better and good FN outcome as House-Brackmann grade II or better.
Results:
For IC tumors and those with up to 9-mm CPA extension, there was no significant difference in the rate of functional hearing preservation (62.2% vs. 63.1%, P =.931) and good FN outcome (93.7% vs. 97.6%, P =.358). For tumors of 10- to 18-mm CPA extension, the rate of hearing preservation (34%) was lower than the other groups (P =.006 and P =.009). In this group, the rate of good FN outcome was lower compared with the IC and 1- to 9-mm tumors (80.8% vs. 93.7%, P =.037 and 97.6%, P =.012). The rate of good FN outcome following the TL approach in a comparable cohort of patients was 100% (P =.003 in comparison with 10-18 mm tumor resected with the MF approach).
Conclusions:
When considering surgical options, patients with >10-mm tumors should be advised that choosing the MF approach for hearing preservation carries a somewhat higher risk of persistent FN dysfunction.
