The long-term follow-up of drainage procedures for petrous apex cholesterol granulomas.

Abstract

To determine the long-term effectiveness of various approaches to surgical drainage of petrous apex cholesterol granulomas. 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). House Ear Clinic, an otologic tertiary care center in Los Angeles, Calif. A total of 25 patients who underwent either transcanal infracochlear, infralabyrinthine, middle fossa, or translabyrinthine drainage and who had at least 1 year of clinical and, in some cases, radiologic postoperative follow-up. Relief or recurrence of symptoms, need for revision surgery, postoperative hearing, appearance on postoperative imaging studies. Twenty-three patients had improvement or complete resolution of preoperative noncranial nerve VIII nerve dysfunction. Hearing was preserved in cases of middle fossa, infralabyrinthine, and infracochlear approaches with serviceable preoperative hearing. Hearing did not improve in cases of total preoperative hearing loss. Of the patients who underwent postoperative imaging, over three fourths had reduction in lesion size and one third developed aeration of the petrous apex. Revision surgery was required in three patients. Recently developed, the infracochlear approach has shown excellent early results. Lesion size was reduced in five of five patients, and the petrous apex contained air in three of five patients who underwent the infracochlear approach. Drainage via the infracochlear and infralabyrinthine approaches offers effective long-term decompression of petrous apex cholesterol granulomas, while preserving hearing.