Asian Journal of Medical Research and Case Reports

Introduction: Stapes surgery is among the most dependable procedures in otology, yet a minority of ears either never achieve the expected closure of the air-bone gap or lose this closure after an initially satisfactory result. Revision surgery in these ears is technically demanding, and its outcome is far less predictable than that of primary surgery. The purpose of this study was to identify the causes of functional failure encountered during re-exploration and to quantify the hearing benefit delivered by revision surgery.

Materials and Methods: We conducted a retrospective descriptive study over a twelve-year period in a single tertiary department, with all procedures performed by the same surgeon. Patients who underwent revision after a primary operation for otosclerosis performed in our unit were included; incomplete files, patients lost to follow-up, and ears with total deafness were excluded. Air- and bone-conduction thresholds were averaged across 500, 1000, 2000, and 4000 Hz, and the air-bone gap was calculated as the difference. High-resolution computed tomography of the temporal bone was obtained in every case before re-exploration. Outcomes were assessed according to the criteria of the American Academy of Otolaryngology-Head and Neck Surgery.

Results: One hundred and sixty-four primary stapedotomies were performed during the study period. Eleven ears (6.7%) developed functional failure, and eight were analysable. The mean age at revision was 41.5 years, with a female predominance of seven to one. Failure was recognised within the first month in three patients and beyond three years in one, with a mean interval of 1.4 years. Computed tomography suggested prosthesis dislocation in four ears. At exploration, a prosthesis-related problem was found in six of the eight ears, with dislocation being the single most common finding. The mean pure-tone average improved from 63.4 dB to 47.5 dB, and the mean air-bone gap narrowed from 39.4 dB to 26.3 dB. A residual gap of 20 dB or less was obtained in six ears (75%), and closure of at least 10 dB was achieved in six ears (75%). Bone conduction deteriorated slightly by approximately 2.6 dB, and no patient developed total deafness.

Discussion: Prosthesis displacement predominated in our series, as it does in most published cohorts, and this finding is reassuring because it is also the most correctable failure mechanism. Our functional results fall within the range reported in the literature for the 20 dB endpoint but fall short at the 10 dB endpoint, which we attribute to the small sample, the absence of laser assistance, and the severity of the preoperative gaps. Careful preoperative counselling remains essential: roughly three out of four patients can expect meaningful improvement, and the possibility of an unchanged or poorer result must be stated plainly