Assessment of recurrent laryngeal nerve function during thyroid surgery

Area of Science:

• Otolaryngology
• Endocrinology
• Surgical Oncology

Background:

• Discrepancies exist in reported rates of recurrent laryngeal nerve (RLN) palsy after thyroidectomy, often due to varied vocal cord function assessment methods.
• Understanding the incidence and natural history of temporary and permanent vocal cord palsy is crucial for patient management post-thyroid surgery.

Purpose of the Study:

• To determine the incidence and natural course of temporary and permanent vocal cord palsy following thyroidectomy.
• To evaluate the utility of intraoperative nerve monitoring in predicting vocal cord palsy outcomes.

Main Methods:

• Prospective data collection from consecutive thyroidectomy patients.
• Utilized intraoperative nerve monitoring with an endotracheal tube device in all cases.
• Assessed laryngeal function via endoscopic examination on postoperative day 1 and at 3 weeks.

Main Results:

• Analyzed data from 102 patients (123 nerves); reported temporary RLN palsy rate of 6.1% and permanent rate of 1.7%.
• Most palsies were detected on postoperative day 1, with all identified by 3 weeks; no preoperative risk factors were found.
• Intraoperative nerve monitoring did not predict vocal cord function outcomes; dysphonia at 3 weeks was a predictor, but not all palsies caused dysphonia.

Conclusions:

• Direct laryngoscopy is the definitive method for assessing vocal cord function post-thyroidectomy.
• Intraoperative nerve monitoring is unreliable for predicting vocal cord function or long-term laryngeal function.
• The observed 4-month recovery for all temporary palsies has implications for planning subsequent surgical procedures.