Effect of intraoperative neuromonitoring on voice quality in total thyroidectomy

Abstract

Aim: Thyroid gland surgery has a risk of serious complications. Advancements in technology have led to improvements in complications but significant challenges to preserving voice and airway function still remain. The purpose of this study was to evaluate voice quality following total thyroidectomy under neuromonitoring and effect of intraoperative neuromonitoring (IONM) on identification of the recurrent laryngeal nerve (RLN) and external branch of the superior laryngeal nerve (EBSLN). Methods: A total of 80 patients scheduled for total thyroidectomy between May 2015 and March 2016 were included in the study. All the RLNs and EBSLNs were identified. Voice assessment included preoperative and postoperative fiberoptic laryngoscopy, analysis of Jitter, Shimmer, and fundamental frequency and the Voice Handicap index-10. Results: Eighty patients were included in this study (71 females, nine males). There was no significant difference between mean initial and post-dissection electromyographic amplitudes with RLN and EBSLN stimulation. The rate of postoperative transient RLN palsy per nerve at risk was 4.375% (7/160) and null for permanent RLN palsy (0%, 0/160). Conclusion: Both subjective and objective assessments revealed preservation of voice quality in patients after total thyroidectomy under neuromonitoring. IONM may be used effectively and safely in order to identify the EBSLN during thyroid surgery.