Otosclerosis: Experience With Stapes Surgery

Introduction Otosclerosis is a disorder in which the footplate of the stapes is replaced by an abnormal bone, thereby affecting sound transmission to the inner ear at the level of the oval window. The solution to this condition is to reestablish this mechanism back to normal via the ossicular chain to the inner ear. The aim of stapes surgery is to improve the hearing level to thresholds appropriate enough to obviate the need for hearing aid. The hearing improvement achieved after surgery often lasts for many years. The purpose of the current study was to review our experience and find out the rate of success related to hearing outcomes after stapedotomy. Methods The patients who were operated for otosclerosis between January 2000 and December 2010 at Aga Khan University Hospital, Karachi, Pakistan were included in the study. The charts were reviewed to collect clinical data regarding stapes surgery. The values of speech reception threshold (SRT) were recorded, and the preoperative and postoperative means were compared with a t-test. The bone conduction (BC) and air conduction (AC) thresholds were evaluated at 0.5 kHz, 1.0 kHz, 2.0 kHz, and 3.0 kHz. The preoperative and postoperative means of air-bone gap (AB-gap) were compared with a t-test. The descriptive frequency was calculated to evaluate postoperative AB-gap in individual patients; patients were grouped with a difference of 10 dB of AB-gap. The SPSS Statistics software (IBM, Armonk, NY) was used for statistical analysis. Results A total of 46 patients were included in the study. There were 15 males and 31 females. The mean age was 35 years (range: 20-56). Thirty-three patients had bilateral otosclerosis; two patients had surgery for both ears, taking the total number of ears operated to 48. The mean preoperative AB-gap was 39, while the mean postoperative AB-gap was 11. The means were compared with a t-test and a p-value of <0.05 was considered significant. The means of preoperative and postoperative SRT were 56.25 and 24.27 respectively. Both means were compared with a t-test, and a p-value of <0.05 was considred significant. Postoperatively, 34 ears had AB-gap of 10 dB (70.8%), 11 (22.9%) had within 20 dB, and three (6.3%) had within 30 dB. Conclusions The success rate related to hearing outcomes in patients operated for otosclerosis was excellent and comparable to that found in the current literature. The wide AB-gap noticed in the majority of our patients may represent a delayed presentation to otolaryngologists, which requires further evaluation.