Abstract:Objective To systematically evaluate the long-term efficacy of autologous fat injection in patients with unilateral vocal cord paralysis with a course of more than 6 months, and to explore the key factors affecting the surgical effect. Methods A prospective cohort study was used to enroll 39 patients who underwent surgery from January 2018 to December 2022. The transplanted fat was obtained by a modified fat treatment technique (two-step gradient centrifugation), and the subjective and objective voice parameters were evaluated before and at 1, 3, 6 and 12 months after surgery, including GRBAS score, voice dysphonia index (VHI), strobe laryngoscopy and acoustic analysis. Results At 12 months after surgery, 84.6% (33/39) of patients had normal pronunciation (G0 grade), and the total VHI score decreased significantly from 68.5±25.3 to 22.7±18.4 (P<0.001). Multivariate regression analysis showed that disease duration (β=-0.32, P=0.004), centrifugation times(β=0.25, P=0.008) and injection accuracy (β=0.41, P=0.002) were independent predictors of surgical outcome. Conclusions Standardized fat treatment process combined with precision injection technology can significantly improve the surgical efficacy, which is a safe and effective method for the treatment of chronic unilateral vocal cord paralysis.