[Influence of etiology on the efficacy of ansa cervicalis anterior root-recurrent laryngeal nerve anastomosis in the treatment of unilateral vocal ford paralysis].

Objective: To explore the efficacy of ansa cervicalis anterior root-recurrent laryngeal nerve (RLN) anastomosis in the treatment of unilateral vocal fold paralysis (UVFP) and to analyze the effect of different pathogenic factors on efficacy. Methods: From January 2010 to January 2022, 428 patients (187 males and 241 females) at Changhai Hospital with UVFP who underwent ansa cervicalis anterior root-RLN anastomosis due to thyroid surgery, thoracic surgery, idiopathic vocal ford paralysis or high cranial base injury were analyzed. The course of nerve injury ranged from 6 to 24 months. Videostroboscopy, auditory perceptual evaluation parameters (GRBAS including Grade, Roughness, Breathiness, Asthenia, Strain), Voice Handicap Index (VHI-10), acoustic analysis including Jitter, Shimmer and noise to harmonic ratio (NHR), maximum phonation time (MPT) and laryngeal electromyography were used to evaluate the surgery efficacy, and the therapeutic difference of the above 4 different etiology patients receiving the operation was compared. Data processing was performed using SPSS 26.0 statistical software, and Wilcoxon signed rank test was used. Kruskal Wallis one-way ANOVA was used for those with equal variance. Results: At 12 months after operation, the affected vocal ford position, vocal ford edge, glottal closure, symmetry and regularity of vocal ford vibration were significantly improved in all four groups (P<0.01). G, R, B, A, S, VHI-10, Jitter, Shimmer and NHR were significantly lower than those before operation, while, MPT was significantly longer (P<0.01). Also, the maximum voluntary motor unit recruitment (VMUR) in the affected thyroarytenoid muscles and posterior cricoarytenoid muscles was significantly improved after surgery (P<0.01). However, the results of thyroid surgery group, thoracic surgery group and idiopathic vocal ford paralysis group were better than those of high cranial base injury group respectively, and the differences were statistically significant (P<0.05). Conclusion: Ansa cervicalis anterior root-RLN anastomosis has an obvious efficacy on the recovery of phonatory function in UVFP patients with different causes, but the high cranial base injury is significantly worse than that of vocal ford paralysis caused by other causes.