Clinical Presentation and Management of Labyrinthine Fistula in Chronic Otitis Media with Cholesteatoma / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Labyrinthine fistula is a potentially serious complication of cholesteatoma. During or after surgery, cholesteatoma induced labyrinthine fistula can result in partial or total destruction of cochleovestibular functions.This study aimed to evaluate the efficacy of preoperative tests for predicting fistulas and postoperative hearing results according to surgical management. MATERIALS AND METHODS: A retrospective study of the clinical records of 1,712 patients who were operated for chronic otitis media with cholesteatoma from January 1979 through April 2001 in a tertiary university hospital in Seoul area. Of 1,712 patients studied, patients who were proved to have labyrinthine fistulas during operation for cholesteatoma were collected. The results of the pre- and postoperative bone conduction pure tone average and pure tone threshold at 4 kHz were analyzed in those patients. The fistula test,the temporal bone CT scan (TBCT) and intraoperative findings were also evaluated. RESULTS: Labyrinthine fistulas were found in 140 (8.2%) patients in this study. Fistulas were most commonly found in the lateral semicircular canal (91.7%) and fistulas in lateral semicircular canal were more accurately detected than the fistula of the other sites either by fistula test or by TBCT. Positive fistula test results and positive temporal bone CT findings in labyrinthine fistula cases were recorded in 36.3% and 74.1% of cases, respectively. Canal wall down mastoidectomy procedures were applied in 134 ears (95.7.%). The cholesteatoma matrix was removed in 129 ears (92.1%). The average bone conduction threshold showed no significant difference between pre- and postoperative evaluations overall. But in matrix-removed group, the change in the bone conduction level was significantly different between patients having fistula same or larger than 2 mm and smaller than 2 mm. CONCLUSIONS:The high resolution temporal bone CT scan is highly recommended for detection of labyrinthine fistulas. The postoperative hearing results are not affected by the type of mastoidectomy procedures but may be affected by the management of cholesteatoma matrix when the fistula is large in this study.