Incidence, Risk Factors, and Natural Outcome of Vocal Fold Paresis in 920 Thyroid Operations with Routine Pre- and Postoperative Laryngoscopic Evaluation

Abstract

BackgroundThe aim of this study was to determine the incidence, risk factors, and spontaneous recovery rate of vocal fold paresis (VFP) with routine laryngoscopy before and after thyroid surgery.MethodsAll consecutive patients undergoing primary or redo thyroid surgery between years 2011–2016 were prospectively registered in an electronic database, and scheduled for pre- and postoperative laryngoscopic vocal fold inspection by otolaryngologists independently of the surgical team.ResultsA total of 920 thyroid operations with 1296 nerves at risk were performed in 866 patients. Pre- and postoperative laryngoscopy was done in 95% and 98%, respectively. Preoperative VFP was detected in 24 (2.8%) patients. New postoperative VFP was found in 53 of 920 operations (5.8%) and in 55 of 1296 nerves at risk (4.2%). After 12 months, 14 had recovered full vocal fold function and eight had near-complete recovery. VFP was permanent after 29 operations (3.2%); two patients were lost to follow-up with uncertain outcome. Of the 1296 nerves at risk, injury was permanent in 30 (2.3%). In multivariate analysis, patients operated for recurrent goiter had nearly nine times higher risk of new VFP (23% rate), whereas patients with malignant histology had three times higher risk of postoperative VFP (up to 22% rate).ConclusionVFP continues to be a serious complication of thyroid surgery, especially in operations for redo goiter and thyroid malignancy. The incidence of VFP may be underestimated unless laryngoscopic examinations are performed routinely.