THE LONG-TERM FOLLOW-UP OF DRAINAGE PROCEDURES FOR PETROUS APEX CHOLESTEROL GRANULOMAS

Objective: To determine the long-term effectiveness of various approac hes to surgical drainage of petrous apex cholesterol granulomas. Desig n: A retrospective cohort study in which patients treated by surgical drainage for petrous apex cholesterol granulomas were followed up for a minimum of 1 year (mean, 4.6 years). Setting: House Ear Clinic, an o tologic tertiary care center in Los Angeles, Calif. Patients: A total of 25 patients who underwent either transcanal infracochlear, infralab yrinthine, middle fossa, or translabyrinthine drainage and who had at least 1 year of clinical and, in some cases, radiologic postoperative follow-up. Main Outcome Measures: Relief or recurrence of symptoms, ne ed for revision surgery, postoperative hearing, appearance on postoper ative imaging studies. Results: Twenty-three patients had improvement or complete resolution of preoperative noncranial nerve VIII nerve dys function. Hearing was preserved in cases of middle fossa, infralabyrin thine, and infracochlear approaches with serviceable preoperative hear ing. Hearing did not improve in cases of total preoperative hearing lo ss. Of the patients who underwent postoperative imaging, over three fo urths had reduction in lesion size and one third developed aeration of the petrous apex. Revision surgery was required in three patients. Re cently developed, the infracochlear approach has shown excellent early results. Lesion size was reduced in five of five patients, and the pe trous apex contained air in three of five patients who underwent the i nfracochlear approach. Conclusion: Drainage via the infracochlear and infralabyrinthine approaches offers effective long-term decompression of petrous apex cholesterol granulomas, while preserving hearing.