The Feasibility Study of Intraoperative RLN Monitoring Using Cricothyroid Membrane‐Inserted Needle Electrodes During Thyroid Surgery

Abstract

AbstractObjectiveThis study evaluated the feasibility, stability, safety, and economy of cricothyroid membrane (CM)‐inserted needle electrodes for recurrent laryngeal nerve monitoring.Study DesignParallel and controlled study.SettingClinical research center for thyroid diseases of Shaanxi province.MethodsA total of 64 patients in the needle electrodes group (104 recurrent laryngeal nerves [RLNs]) and 44 patients in the endotracheal tube (ETT)‐based electrodes group (80 RLNs) underwent monitored thyroidectomy. The evoked electromyography (EMG) signals detected by the 2 electrodes were recorded and analyzed. The changes in EMG during Berry's ligament traction and tracheal displacement were compared. All patients underwent preoperative and postoperative laryngoscopy within 1 week.ResultsBoth electrodes successfully recorded typical evoked laryngeal EMG waveforms from RLNs. The needle electrodes recorded relatively higher amplitudes and similar latencies compared to ETT‐based electrodes. The evoked EMG signals attributed to needle electrodes could accurately predict the function of RLNs with 100% sensitivity and specificity. The reduction in the recorded amplitudes attributed to needle electrodes was higher than that observed with ETT‐based electrodes during Berry's ligament traction or trachea displacement, whereas a similar increase in the latencies was recorded in the 2 groups. Particularly, Berry's ligament traction was more likely to lead to EMG amplitude reduction and latency prolongation. The needle electrodes group recorded 2 cases of minor bleeding on the CM. The needle electrodes were more cost‐effective than ETT‐based electrodes.ConclusionThe CM‐inserted needle electrodes are feasible, stable, safe, and economical for RLN monitoring, and they provide an alternative novel intraoperative neural monitoring format for thyroid surgeons.