Surgical effects of type-I thyroplasty and fat injection laryngoplasty on voice recovery

Objective: Type-I thryroplasty, also known as medialization thyroplasty (MT) and autologous fat injection laryngoplasty (FIL) are one of the main surgical treatments for unilateral vocal fold paralysis (UVFP). Both procedures have the same concept of completing the glottal closure by medializing the vocal fold, although the surgical approaches are quite different. In order to assess these surgical effects, we examined the treatment outcomes and benefits of the two surgeries. Methods: We collected data from the 135 phonosurgeries that we performed out of 375 patients with UVFP at Osaka Voice Center, Osaka Kaisei Hospital from January 2009 to February 2013. After excluding cases with glottal level differences on phonation, either MT or FIL were performed on 80 cases. The inclusion criteria for the present study were: (1) patients had no history of previous phonosurgery, and (2) functional evaluations were available before/after surgery. Consequently, 43 participants (12 for MT and 31 for FIL) were enrolled in this study. Surgical effects were evaluated by means of the maximum phonation time (MPT), pitch period perturbation quotient (PPQ), amplitude perturbation quotient (APQ), and harmonic to noise ratio (HNR) just before, one month, and 6 months after surgery. Results: Both MT and FIL showed significant improvement in MPT (MT, p = 0.005; FIL, p < 0.001) and PPQ (MT, p = 0.047; FIL, p = 0.041) at 1 month postoperation. We also compared the variation of each variable between the two procedures, but there were no significant differences in these parameters. However, MPT, APQ, and HNR at the post-MT after 6 months worsened compared to those at 1 month post-treatment, whereas MPT showed only a slight decrease from the 1st month to the 6th month in those with FIL. Conclusion: Both MT and FIL were effective for the voice recovery in patients with UVFP. Our findings suggest that surgical results in FIL might be better than those in MT 6 months after surgery, although there were no significant differences between these two procedures 1 month postoperation. (C) 2020 Oto-Rhino-Laryngological Society of Japan Inc. Published by Elsevier B.V. All rights reserved.