Clinical experience with the continuous intraoperative nerve monitoring system in mediastinoscopic esophagectomy

The specific cause of operative manipulation has not yet been identified. Here, we report a successful case for the detection of impending recurrent laryngeal nerve (RLN) injury during mediastinoscopic subtotal esophagectomy using the continuous intraoperative nerve monitoring system (CIONM). After attaching a monopolar automatic periodic stimulation electrode on the vagal nerve, the latency and the amplitude of the vocal cord contractility were monitored as the RLN function. During the nodal dissection around the left RLN, a 50% or greater decrease in the amplitude relative to the baseline values was temporarily recorded by retracting the left RLN from the dorsal to the ventral direction. However, it improved promptly after relieving the retraction of the RLN. Throughout the operation, the amplitude values of both RLNs were kept at 50% or greater relative to the baseline value, and as a result, RLN palsy did not occur after surgery. CIONM may be useful in preventing irreversible RLN injury by monitoring the real-time function of the RLN and alerting the dangerous maneuver leading to decreased levels of vocal cord contractility.