Intraoperative Monitoring of the Recurrent Laryngeal Nerve with Electromyography Endotracheal Tube in Anterior Cervical Discectomy and Fusion

Objective Recurrent laryngeal nerve (RLN) injury is common complication after anterior cervical discectomy and fusion (ACDF). In the present study, we evaluated RLN function during ACDF surgery using intraoperative RLN monitoring with an electromyography-endotracheal tube (EMG-ET). Methods In the present study, we retrospectively compared the postoperative RLN injury outcomes between patients who had undergone ACDF with and without an EMG-ET at Vajira Hospital from March 2017 to March 2022. Results The analysis included 85 patients, 58 (68.2%) of whom had undergone surgery without an EMG-ET and 27 (31.8%) with an EMG-ET. Of the no EMG-ET group, 8 (13.8%) and 1 (1.7%) patient had developed immediate postoperative dysphagia and hoarseness, respectively, with complete recovery within 12 months. In the EMG-ET group, 2 (7.4%) and 1 (3.7%) patient had developed dysphagia and hoarseness, respectively, with complete recovery within 3 months for all 3 patients. Persistent postoperative RLN palsy had occurred in 5 patients (8.6%) without the EMG-ET but in none of the patients with the EMG-ET. The sensitivity and specificity for the use of intraoperative EMG-ET to detect a potential RLN injury were 67.0% and 96.0%, respectively. The use of an EMG-ET reduced the retractor time (P = 0.003), and a retractor time of <70 minutes was associated with a decreased incidence of postoperative RLN injury (odds ratio, 0.122; 95% confidence interval, 0.015-0.981; P = 0.048). Conclusions The use of an EMG-ET for RLN monitoring during ACDF surgery was helpful in detecting postoperative RLN injury with fair sensitivity and high specificity and resulted in a shorter retractor time, thereby significantly reducing the risk of postoperative RLN injury.