Multiparameter Analysis of Titanium Vocal Fold Medializing Implant in an Excised Larynx Model

Abstract

Objectives: We evaluated the efficacy of the titanium vocal fold medializing implant (TVFMI) for the treatment of unilateral vocal fold paralysis (UVFP) on the basis of acoustic, aerodynamic, and mucosal wave measurements in an excised larynx setup. Methods: Measurements were recorded on 8 excised canine larynges with simulated UVFP before and after medialization with a TVFMI. Results: The phonation threshold flow (p < 0.001) and phonation threshold power (p = 0.008) decreased significantly after medialization. The phonation threshold pressure also decreased, but this difference was not significant (p = 0.081). Jitter (p = 0.005) and shimmer (p = 0.034) decreased significantly after medialization. The signal-to-noise ratio increased significantly (p = 0.05). Differences in mucosal wave characteristics were discernible but not significant. The phase difference between the normal and paralyzed vocal folds (p = 0.15) and the amplitude of the paralyzed vocal fold (p = 0.78) decreased. The glottal gap decreased significantly (p = 0.004). Conclusions: The TVFMI was effective in achieving vocal fold medialization, improving vocal aerodynamic and acoustic characteristics of phonation significantly and mucosal wave characteristics discernibly. This study provides objective, quantitative support for the use of the TVFMI in improving vocal function in patients with UVFP.