Does stapedotomy improve high frequency conductive hearing?

Abstract

Objectives Stapedotomy is performed to address conductive hearing deficits. While hearing thresholds reliably improve at low frequencies (LF), conductive outcomes at high frequencies (HF) are less reliable and have not been well described. Herein, we evaluate post‐operative HF air‐bone gap (ABG) changes and measure HF air conduction (AC) thresholds changes as a function of frequency. Methods Retrospective review of patients who underwent primary stapedotomy with incus wire piston prosthesis between January 2016 and May 2020. Pre‐ and postoperative audiograms were evaluated. LF ABG was calculated as the mean ABG of thresholds at 250, 500, and 1000 Hz. HF ABG was calculated at 4 kHz. Results Forty‐six cases met criteria. Mean age at surgery was 54.0 ± 11.7 years. The LF mean preoperative ABG was 36.9 ± 11.0 dB and postoperatively this significantly reduced to 9.35 ± 6.76 dB, (P < .001). The HF mean preoperative ABG was 31.1 ± 14.4 dB and postoperatively, this also significantly reduced to 14.5 ± 12.3 dB, (P < .001). The magnitude of LF ABG closure was over 1.5 times the magnitude of HF ABG closure (P < .001). The gain in AC decreased with increasing frequency (P < .001). Conclusion Hearing improvement following stapedotomy is greater at low than high frequencies. Postoperative air bone gaps persist at 4 kHz. Further biomechanical and histopathologic work is necessary to localize postoperative high frequency conductive hearing deficits and improve stapedotomy hearing outcomes. Level of Evidence 4, retrospective study.

A comparative study of changes in audiological characteristics when using endoscopic and microscopic stapes surgery in patients with otosclerosis

“…There were no significant differences among BC-LF, BC-MF, and BC-HF in the MSS group. Similarly, Roychowdhury et al found that ABG-LF improved significantly more than ABG-LF after stapedotomy (12), and presented a simple linear regression model demonstrating that ΔAC (y) decreases as the frequency (x) increases [y=-0.003853x+34.76 (R 2 =0.951), P<0.001], and indicated that there was no significant difference between preoperative and postoperative thresholds at 8 kHz. One hypothesis could be that the surgical wound is on the vestibular window and HF soundwaves cause vibrations only on the basement membrane around the vestibular window, therefore LF and MF data have better post-stapedotomy outcomes than HF.…”

“…Shiao et al and Babighian et al demonstrated significant improvement in average air conduction (AC) and air-bone gap (ABG) (P<0.001) and no difference in bone conduction (BC) after surgery were reported in their cases (10,11). In their study, Roychowdhury et al reported that low-frequency (LF) AC and ABG improved significantly more after stapedotomy than high-frequency (HF) AC and ABG (12).…”