What is the impact of continuous neuromonitoring on the incidence of injury to the recurrent laryngeal nerve during total thyroidectomy?

BACKGROUND Continuous intraoperative neuromonitoring may facilitate reversal of intraoperative injurious operative maneuvers in comparison with intermittent intraoperative neuromonitoring. The aim of this study was to evaluate the impact of the routine use of continuous intraoperative neuromonitoring on intraoperative injuries to the recurrent laryngeal nerve. METHOD This study was a prospective case series with retrospective analysis of consecutive patients undergoing total thyroidectomy from August 2013 to August 2019. During this period, intermittent intraoperative neuromonitoring (before Mar 2016) and continuous intraoperative neuromonitoring (after Mar 2016) were used in all patients. RESULTS We reviewed the outcomes of 603 patients (466 female patients) comprising 236 who underwent intermittent intraoperative neuromonitoring and 367 who underwent continuous intraoperative neuromonitoring. Intraoperative adverse electromyography events (>50% decrease in amplitude between VN1 and VN2) were observed in 87 patients (14.5%) and were less frequent in the continuous intraoperative neuromonitoring group (10.6 vs 20.3%, P = .001). Intraoperative loss of signal (electromyography events with VN2 ≤100μV) were observed in 35 patients (5.8%) without any difference between the 2 groups of patients (5.2 vs 6.8%, P = .415). Postoperative recurrent laryngeal nerve palsies were observed in 36 patients (5.9%) without any difference between the 2 groups of patients (4.9 vs 7.6%, P = .168). CONCLUSION The routine use of continuous intraoperative neuromonitoring improves the rate of intraoperative adverse electromyography events but does not impact significantly the rates of loss of signal and recurrent laryngeal nerve palsy.