Combined Transmastoid/Middle Fossa Approach for Intracranial Extension of Middle Ear Cholesteatoma

A retrospective review was performed of patients treated for middle ear cholesteatoma with bone defects of the skull base via a combined transmastoid/middle fossa approach at the University of Tsukuba Hospital from 2006 through 2011 to determine the safety and effectiveness of a combined transmastoid/middle fossa approach for the treatment of cholesteatoma involving the middle cranial fossa. The bone defects of the skull base were reconstructed with a galeal flap pedicled with a parietal branch of the superficial temporal artery and an autologous bone flap. The clinical and radiological data were analyzed. This series included 8 patients (6 men and 2 women) with a mean age of 46.3 years (range 10-67 years). One of the patients preoperatively exhibited meningoencephalocele of the middle fossa skull base, and in the remaining 7 patients, petrous bone involvement such as involvement of the supralabyrinthine cells was observed. The cholesteatoma lesion was totally removed and inner ear function preserved in all the patients. Cerebrospinal fluid leakage was observed in 1 patient during and after the surgery. Neither meningitis nor recurrence was observed in any patient during the follow-up periods (mean 29.4 months, range 6-64 months). The combined transmastoid/middle fossa approach allowed complete removal of cholesteatoma with middle cranial fossa involvement while preserving hearing and preventing postoperative cerebrospinal fluid leakage and meningitis.