Types and Timing of Therapy for Vocal Fold Paresis/Paralysis After Thyroidectomy: A Systematic Review and Meta-Analysis

Objectives. To perform a systematic literature review to evaluate the type and timing of therapy for vocal fold paresis/paralysis after thyroidectomy and develop a primary decision-making pathway. Study Design. Meta-analysis. Methods. Four databases and one journal were searched using the key words of "thyroidectomy," "vocal cord paresis/paralysis," and "therapy." Study quality was evaluated using the Cochrane Collaboration's risk of bias tools. Data regarding type and timing of therapy were extracted from 39 articles. Odds ratios (ORs), relative risk (RR), 95% confidence interval, and heterogeneity were recorded. Logistic regression analysis was performed to determine the relationships between timing and OR/RR. Results. Among the 13 studies investigating unilateral paresis/paralysis, five focused on early therapy (0-6 months). In these studies, the OR for clinical heterogeneity was significantly higher after neurolysis than after injection laryngoplasty and voice training (Q = 17.002, I-2 = 78%, P = 0.000), and the RR for heterogeneity was significantly higher after injection laryngoplasty at >= 12 months than <12 months (Q = 9.984, I-2 = 89.9%, P = 0.002). In the 26 studies that investigated bilateral paresis/paralysis, the OR for heterogeneity was significantly higher for bilateral posterior cordectomy than for endolaryngeal laterofixation (Q = 3.510, I-2 = 71.5%, P = 0.061) and laser arytenoidectomy with posterior cordectomy (Q = 2.90, I-2 = 65.6%, P = 0.088). Conclusions. For unilateral vocal fold paresis/paralysis after thyroidectomy, we recommend absorbable mass injection laryngoplasty, voice training, and neurolysis during the first 12 months but laryngeal reinnervation after 12 months. For bilateral vocal fold paresis/paralysis, we recommend early laterofixation and combined laser arytenoidectomy with posterior cordectomy after 12 months.