Clinical presentation and management of labyrinthine fistula caused by chronic otitis media

To describe the clinical presentation and surgical management of patients w ith chronic otitis media complicated by labyrinthine fistula and to determi ne clinical indicators that predict postoperative hearing outcome, I perfor med a retrospective analysis at an academic tertiary care center. Thirty-fo ur patients with labyrinthine fistula as a complication of chronic otitis m edia, documented at mastoidectomy, underwent postoperative audiometry. The median age was 50 years, and the duration of otologic symptoms ranged from 2 months to more than 40 years. On presentation, 3 patients had anacusis in the affected ear, while in the others, the pure tone average for bone cond uction at the 0.5-, 1-, 2-, and 4-kHz frequencies was 34 dB hearing level. Nineteen patients (56%) complained of dizziness on presentation. The fistul a test was positive in 14 of 28 patients (50%). The fistula was detected ra diologically in 10 of 24 patients (42%). Cholesteatoma was present in 33 of 34 patients (97%). The lateral semicircular canal was the most common site of labyrinthine fistula. The cholesteatoma matrix was completely removed i n 29 of 33 cases and exteriorized in the remaining 4. Of the 31 patients wi th measurable hearing preoperatively, anacusis occurred in 8 (26%). In 6 of these, the preoperative pure tone average for bone conduction was greater than 50 dB hearing level, and cholesteatoma matrix and granulation tissue i nvading the membranous labyrinth were found at surgery. I concluded that in chronic otitis media, labyrinthine fistulas occurred almost exclusively in the presence of a cholesteatoma. Postoperative hearing outcome correlated with the size of the fistula and the presence of granulation tissue invadin g the labyrinth, which could be predicted by the preoperative audiometry.