Middle Fossa Approach for Hearing Preservation

The middle cranial fossa (MCF) approach has a rich history and is fundamental in the armamentarium of the skull base surgeon. This approach provides unparalleled exposure of the lateral internal auditory canal and the optimal conditions for hearing preservation in select individuals. Hearing preservation hinges on what constitutes “hearing” and “preservation,” with many definitions proposed and used. When considering those patients with preoperative AAO Class A or B hearing, preservation of postoperative AAO Class A or B hearing ranges from 48% to 74% in larger series. When preserved in the initial postoperative period, hearing generally appears to maintain long-term durability. The chances for hearing preservation decrease with poorer preoperative hearing and with larger tumors; fundal fluid cap and nerve of origin may or may not influence rate of hearing preservation. Complications, including facial nerve outcomes, are similar to other approaches, in properly selected patients <65 years of age. The MCF approach demands meticulous surgical technique in both bony exposure and tumor removal. Patients <65 years old with smaller tumors and serviceable hearing are ideal candidates.