INTRAOPERATIVE ELECTROPHYSIOLOGIC MONITORING OF THE RECURRENT LARYNGEAL NERVE

Intraoperative electrophysiologic monitoring of the recurrent laryngea l nerve was performed with a commercially available device consisting of an endotracheal tube with integrated stainless-steel-wire surface E MG electrodes positioned at the level of the true vocal cords. Forty-t wo recurrent laryngeal nerves were successfully monitored with this sy stem in 31 patients undergoing thyroidectomy or parathyroidectomy, In all cases, evoked EMG responses were elicited by direct electrical rec urrent laryngeal nerve stimulation. Stimulus thresholds for evoked res ponses ranged from 0.2 to 0.6 mA (mean 0.3 mA) for the 37 nerves with preoperative ipsilateral normal vocal cord mobility, Mechanically evok ed potentials with acoustic signals were also detected during the surg ical procedures related to recurrent laryngeal nerve manipulation, It may be concluded that surface electrode monitoring of the recurrent la ryngeal nerve with this system provides a simplified, noninvasive tech nique that is as sensitive as monitoring with intramuscular laryngeal electrodes.