Recurrent Laryngeal Nerve Monitoring during Thoracoscopic Esophagectomy

Introduction There have been several reports on the feasibility and curability of thoracoscopic esophagectomy, which may reduce injury to the thoracic cage and decrease the invasiveness of surgery. Although the recurrent laryngeal nerve (RLN) is identified and kept intact during operations, RLN palsy sometimes occurs. Currently, surgical aides, including intraoperative neurological monitoring, are being utilized to avoid RLN injury during thyroid surgery. This system is utilized during thoracoscopic esophagectomy in the prone position. Patients and methods Seven consecutive patients (six men, one woman; age range 62–74 years; mean 68 years) were included. Patients underwent general anesthesia and were intubated using the NIM TriVantage™ electromyography (EMG) tube. One-lung ventilation was performed with an endobronchial blocker. Thoracoscopic esophagectomy was performed in the prone position. The nerve stimulator was calibrated to 0.5 mA, and after the RLN was visually identified it was subsequently stimulated, which also confirmed normal machine functioning. In some situations, in the absence of a response, stimuli were increased to 1.0 mA and then 2.0 mA. Results Intraoperatively, all seven patients had their nerve signals monitored. In one case, a nerve signal disappeared after complete lymph node dissection along the left RLN. This system could identify the site of injury, and the thoracoscopic magnified view allowed the disrupted point to be located precisely. When we checked VTR after surgery, the source of injury was one point tension of the nerve pulled by fiber during lymph node dissection. Conclusions Intraoperative RLN monitoring during thoracoscopic esophagectomy in the prone position, with one-lung ventilation performed using the TriVantage™ EMG tube and a bronchial blocker, is technically feasible, easy, and reliable.