Laser Stapedotomy Using SMART Piston: 5-Year Results

Abstract

Objective: The SMART piston is composed of a nitinol-based hook and a Teflon-based piston. Nitinol is a metal alloy of nickel and titanium that allows self-crimping by heat activation. The aim of this study is to evaluate the long-term (5 years) auditory results after the use of the SMART piston in primary laser stapedotomy.

Method: This is a retrospective review of prospectively collected data. The 5-year postoperative follow-up data for 32 patients is presented. Preoperative pure tone audiograms recording air and bone conduction thresholds at 0.5, 1, 2, 3, and 4 kHz were recorded. Postoperative pure tone audiograms at the same frequencies were recorded after 6 weeks, 6 months, 1, 2, 3, 4, and 5 years. Air-bone gaps and pure tone averages at 0.5, 1, 2, and 3 kHz were calculated.

Results: The 4-frequency pure tone average of 0.5, 1, 2, and 3 kHz had a mean preoperative value of 58.4dB (SD ± 14.3dB) in air-conduction thresholds. This has shown a drop in mean thresholds to 28.7 dB (SD ± 11.0 dB) in the 5-year follow-up. The air-bone gap also decreased from 30.1 dB (SD ± 9.6 dB) to 1.5 dB (SD ± 3.8 dB), which was statistically significant (P = .001). There was no significant change in the pure tone average bone conduction threshold when comparing the preoperative thresholds (28.3 dB, SD ± 12.5dB) and postoperative thresholds (23.9dB, SD ± 11.1 dB; P = .551).

Conclusion: Results demonstrate that the SMART piston provides excellent long-term auditory outcome. The ease of the self-crimping and the tightness of the crimp provide the advantage of long-term results.