Intraoperative electromyogram monitoring of the recurrent laryngeal nerve: experience with an intralaryngeal surface electrode. A method to reduce the risk of recurrent laryngeal nerve injury during thyroid surgery

Abstract

Introduction: A clinical method to localize the recurrent laryngeal nerve intraoperatively in order to minimize the risk of accidental injury is presented.

Methods and results: By means of an electrode, the nerve was stimulated by a pulsed contact current. The resulting muscle potential was detected using an electrode placed in the larynx. We applied this technique during the time period between 1 January 1997 and 31 December 1998. In 96 cases of primary thyroid resection, the recurrent nerve was identified 167 times. The patients were operated on for nodular thyroid (n=85), Grave's disease (n=9) and malignant papillary goiter (n=2). Retrospectively, the rate of intraoperative nerve injury, equivalent to the rate of postoperative transient and permanent nerve palsy, was 1.04% in the 96 patients and 0.60% with respect to the 167 nerves at risk. The rate of failure of the method was 7.29%.