Efficacy of Intraoperative Neuromonitoring during Thyroidectomy with Transcutaneous Adhesive Skin Electrodes

Abstract

Background and Objectives Variable types of electrodes for intraoperative neuromonitoring (IONM) during thyroid surgery have been introduced to make up for the shortcomings of conventional endotracheal electromyogram tube. In this study, we sought to evaluate the efficacy of transcutaneous adhesive skin electrodes for IONM of recurrent laryngeal nerve (RLN) during thyroidectomy.Subjects and Method A total 97 nerves at risk of 80 patients were enrolled in this study. Two disposable adhesive skin electrodes were attached at both upper margins of thyroid cartilage. Using NIM 3.0 system (Medtronic), we recorded the amplitude and latency of signals of vagus nerve and RLN following the standard procedure of IONM. Clinicopathologic factors as well as the preoperative and postoperative vocal cord functions of the patients were analyzed.Results IONM was successful in all nerves at risk without any false loss of signals. There were no complications nor any significant time delay due to adhesive skin electrodes. The mean amplitudes from the vagus nerve (V1) and RLN (R1) were 230.64 µV and 293.48 µV, respectively. Two nerves at risk showed loss of signal and the two patients showed postoperative temporary vocal cord paralysis. The amplitude of signals from the vagus nerve (V1, V2) was significantly higher in the lower body mass index (BMI) group compared to that of the higher BMI group.Conclusion IONM using transcutaneous skin electrodes may be considered as an alternative technique for IONM during thyroid surgery.

Prediction of Voice Outcomes After Hemithyroidectomy Using Skin Electrode Intraoperative Neuromonitoring

“…Prior research has demonstrated that the median amplitude of vagus nerve stimulation using the attached electrodes typically measures around 200 μV, which is less than that of the EMG tube. 15) Our current study yielded comparable results (Table 2), with the reduced intensity attributed to signal attenuation during the transmission of sig-nals from the vocal cord muscles to the skin.…”

“…While previous research has examined the pre-and postoperative amplitude ratios of R1 to R2 and V1 to V2, 15) no prior studies have explored the connection between intraoperative nerve monitoring parameters and voice outcomes. In this study, we hypothesized that a larger difference in amplitude was associated with more severe nerve damage and worse voice change.…”