Objective: Describe the outcomes of treatment for patients with cholesteatomas that are medially invasive to the otic capsule, petrous apex, and/or skull base. Study Design: Retrospective case series Setting: Two tertiary care academic centers. Patients: Patients surgically managed for medially-invasive cholesteatoma at two tertiary care institutions from 2001 to 2017. Interventions: Surgical management of medially-invasive cholesteatomas. Main Outcome Measures: The presenting symptoms, imaging, pre- and post-operative clinical course, and complications were reviewed. Results: Seven patients were identified. All patients had pre-operative radiographic evidence of invasive cholesteatoma with erosion into the otic capsule beyond just a lateral semicircular canal fistula. Five patients had a complex otologic history with multiple surgeries for recurrent cholesteatoma including three with prior canal wall down mastoidectomy surgeries. Average age at the time of surgery was 41.3 years (range 20-83). Two patients underwent a hearing preservation approach to the skull base while all others underwent a surgical approach based on the extent of the lesion. Facial nerve function was maintained at the pre-operative level in all but one patient. No patient developed cholesteatoma recurrence. Conclusions: The medially-invasive cholesteatoma demonstrates an aggressive, endophytic growth pattern, invading into the otic capsule or through the perilabyrinthine air cells to the petrous apex. Surgical resection remains the best treatment option for medially-invasive cholesteatoma. When CSF leak is a concern, a subtotal petrosectomy with closure of the ear is often necessary.
COMPARATIVE-ANATOMICAL STUDIES ON THE BONY OTIC CAPSULE AND OTIC SAC VARIES OF VERTEBRAL ANIMALS
