Preserving bone conduction in patients with labyrinthine fistula.

The management of labyrinthine fistula is a controversial issue. Hearing preservation represents a major challenge. Retrospective study of 31 patients with labyrinthine fistula confirmed intra-operatively during cholesteatoma surgery. In all cases, total matrix removal was performed, and the fistula covered with bone dust, periostium and/or cartilage. Twenty-five patients received a high intra-operative dosage (500 mg) of intravenously applied steroids at least 15 min before handling the fistula. Outcome measurements included comparison of the pre-operative and post-operative bone conduction to assess inner ear function. The results were, the fistula was located in the lateral semicircular canal (LSC) in 22 patients (71.8%) and in the oval window in eight. One patient had a double localization in the superior and lateral semicircular canals. Out of the LSC fistulas, five patients (16.12%) had a fistula type I, 8 had type IIa (25.8%), four (12.9%) type IIb, and six patients type III (19.35%). Three out of eight patients with fistula located in the oval window had a total absence of the footplate, other four presented a partial anterior resorption at the level of the fissula antefenestram and the remaining one had a fractured platina. Pre-operatively, the bone conduction displayed a mean threshold of 35 dB. Twenty-two (85%) out of 26 patients treated intra-operatively with steroids showed preservation or improvement of bone conduction. Patients with fistulas of the oval window, type I, IIa and III fistulas in the LSC treated with cortisone presented good sensorineural hearing outcome (preservation or significant improvement of inner ear function in the majority of cases-91%); the auditory results for group IIb were inconclusive. Five patients did not receive steroids, four of them developed partial sensorineural hearing loss and one went deaf. To conclude, cholesteatoma surgery with a single-staged matrix removal on perilymphatic fistulas, after intra-operative intravenous administration of a high dosage of steroids followed by a multilayer closure of the fistula achieved a hearing preservation or improvement in 85% of our patients.