Cholesteatoma invasion into the internal auditory canal.

Cholesteatoma invasion into the internal auditory canal (IAC) is rare and usually results in irreversible, complete hearing loss and facial paralysis on the affected side. This retrospective study examines the clinical characteristics of seven patients with cholesteatoma invading the IAC, analyzes possible routes of the cholesteatoma's extension and describes the surgical approaches used and patient outcome. Extension to the IAC was via the supralabyrinthine route in most patients. A subtotal petrosectomy, a translabyrinthine approach or a middle cranial fossa approach combined with radical mastoidectomy were required for the complete removal of the cholesteatoma. All seven patients presented with some preoperative facial nerve palsy. The facial nerve was decompressed in four patients and facial nerve repair was performed in three others, two by hypoglossal-facial anastomosis and one by a greater auricular nerve interposition grafting. All patients ended up with total deafness in the operate ear. At 1 year following surgery, the facial nerve function was House-Brackmann grade III in six cases and grade II in one. In conclusion, cholesteatoma invading the IAC is a separate entity with characteristic clinical presentations, require a unique surgical approach, and result in significant morbidity, such as total deafness in the operated ear and impaired facial movement.