Neuromonitoring in Thyroid Surgery: The View of the Laryngologist

Abstract

BACKGROUND: In thyroid surgery, identifying the recurrent laryngeal and the superior laryngeal nerve under direct vision reduces the incidence of nerve injury. METHODS: Neuromonitoring, consisting of the continuous depiction of electromyography (EMG) signals and discontinuous nerve stimulation and interpretation during the surgical procedure, is an established part of standard ENT procedures, e.g. surgery of the parotid gland with monitoring of the facial nerve. This technique has been introduced into surgical procedures for the thyroid gland in many surgical centres. RESULTS: Also in thyroid surgery, neuromonitoring can be a useful tool for identifying and monitoring the laryngeal nerves. Reported limitations of neuromonitoring in thyroidectomy are often caused by inadequate use of the equipment and lack of knowledge about neurophysiology in EMG monitoring. Recent studies have raised questions and pointed out pitfalls concerning technical procedure, sensitivity, postoperative outcome, and documentation; these issues are addressed by the laryngologist with many years of experience in recurrent nerve palsy, its clinical diagnosis, and its conservative and surgical treatment. CONCLUSIONS: By understanding and using neuromonitoring techniques, the surgeon is able to minimize the risk of recurrent and superior laryngeal nerve injury.