The Profile of Otoacoustic Emissions and Multifrequency Tympanometry in Otosclerotic Patients Undergoing Two Types of Stapes Surgery: Small Fenestra and Microtraumatic Stapedotomy

BACKGROUND: Otoacoustic emissions (OAEs) are influenced in otosclerosis. The aim of the current study was to investigate the profile of transient evoked (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) in association with multifrequency tympanometry measures in otosclerotic patients undergoing 2 types of stapes surgery: small fenestra and microtraumatic stapedotomy. MATERIAL/METHODS: A retrospective analysis of prospectively collected data was conducted evaluating 51 otosclerotic patients and 50 normal hearing subjects. Small fenestra and microtraumatic stapedotomy were performed in 27 and 24 patients, respectively. Pure tone audiometry (PTA) was always measured. Detection of TEOAEs and DPOAEs at 5 frequency steps (1, 1.4, 2, 2.8, and 4 kHz) preoperatively and at 2 and 5 months postoperatively, stratified by the type of surgery, represented the main goal of the study. Resonant frequency derived by multifrequency tympanometry was also evaluated. RESULTS: All patients demonstrated improvement in hearing level postoperatively, with significant closure of air-bone gap on PTA. Resonant frequency values returned to normal after microtraumatic stapedotomy but were exceedingly decreased following the small fenestra technique. The detection of both TEOAEs and DPOAEs was improved, but when the detection was stratified by the tested frequencies, significant increase in the number of patients with detectable OAEs was observed, mainly during testing at 1 and 1.4 kHz. CONCLUSIONS: Otosclerotic patients exhibited improvement in the detection of OAEs, particularly at low frequencies, after both procedures. Resonant frequency was normalized following the microtraumatic stapedotomy, whereas it is over-decreased after the small fenestra technique.