Hearing Results in 151 Primary Stapedotomies for Otosclerosis: The Effects of Using Different Audiologic Parameters and Criteria on Success Rates.

Objective: To describe the 151 hearing results of primary stapedotomy for otosclerosis using different criteria of success rates.

Design: Retrospective case series of 151 patients with a diagnosis of otosclerosis and operated on by the same surgeon with the same technique, using a CO2 laser. Patients with revision surgery were excluded. The audiometric data were extracted from the patient files and divided into three groups: early postoperative follow-up (<1 mo after surgery), mid-term follow up (between 1 mo and 1 yr), and late postoperative follow-up (>1 yr).

Results: The postoperative air-bone gap (ABG) was 10 dB or less in 45.2% in the mid-term follow up. For this same follow-up, ABG closure less or equal than 20 dB was achieved in 95.6% of cases. The lower percentage of patients with a postoperative ABG closure of less than or equal to 10 dB can be due to the high rate of bone conduction (BC) overclosure of 15.65%. The functional success described as an air conduction (AC) threshold less than or equal to 30 dB was achieved in 52.2% of patients. The mean speech reception threshold (SRT) in the mid-term follow up was 27.4 dB. The analysis of the data according to the Amsterdam Hearing Evaluation Plots (AHEPs) shows a success rate of 87% at early follow-up.

Conclusions: The success rate is mainly dependent on the definition and criteria as a measure of success. An analysis of the evolution of the BC is mandatory to avoid a false positive success rate when the ABG closure is used. Therefore, the use of the AHEPs would acquire additional information. The hearing outcome has also been based on the speech audiometry and the number of patients achieving an AC less than or equal to 30 dB as a more realistic measure of success. Our series confirms good long term hearing results achieved in stapedotomy surgery with the CO2 laser.