Injection laryngoplasty using hyaluronic acid for Chinese patients with unilateral vocal fold paralysis : an acoustic, durational and perceptual study

Abstract

The study evaluated the surgical efficacy of injection laryngoplasty (IL) with respect to perceptual voice-related quality of life (QOL), acoustic and aerodynamic measurements in patients with unilateral vocal fold paralysis (UVFP). In a longitudinal and prospective clinical cohort study, 14 patients with UVFP who received injection laryngoplasty with hyaluronic acid (Restylane) were examined preoperatively, 1 week, 1 month, and 3 months postoperatively. The patients’ voice was evaluated by self-perception questionnaire (Voice Handicap Index, VHI) and objectively acoustical as well as durational measurements. Patients’ performance in Cantonese lexical tone production was also evaluated in terms of percent correct identification. Results of VHI showed significant improvement in vocal quality immediately after injection. IL yielded a significant decrease in percent jitter and shimmer in dB, and a significant increase in signal-to-noise ratio (SNR). Whereas discernible increment in the duration of maximum phonation time (MPT) was elicited, the procedure significantly improved UVFP patients’ ability to produce HL, HR and LR tones. The improvement observed in all vocal and QOL parameters was maintained for at least 3 months after injection. Results of this paper showed that the treatment effect of IL was immediate and sustainable. The study provides objective evidence for the application of IL on Cantonese- speaking patients with UVFP.