Thyroid cartilage needle vs. endotracheal tube electrodes in EBSLN monitoring during thyroidectomy

During thyroidectomy, both needle electrodes (NE) and endotracheal tube electrodes (ETE) can be used. Incomplete contact of the endotracheal tube electrode with the vocal cords, endotracheal tube electrode may hinder an optimal outcome and even result in an inability to obtain an electromyography wave while neuromonitoring the external branch of the superior laryngeal nerve (EBSLN). There is no study that compares NE and ETE for EBSLN monitoring. Therefore, this study compares NE and ETE recordings during EBSLN monitoring. Twenty-six consecutive patients undergoing total thyroidectomy were included in this study. Intraoperative neuromonitoring was performed simultaneously with both NEs and ETEs. Pre-resection (V1, R1, and S1) and post-resection (V2, R2, and S2) amplitudes and latencies were recorded for both types of electrodes. The Mann-Whitney U test was used for statistical analysis. Twenty-one women and five men were included, and 52 nerves at risk were evaluated. The mean amplitudes for right S1 (314 vs. 168 µV, p = 0.009) and right S2 (428 vs. 161 µV, p: 0.001) and for left S1 (346 vs. 229 µV, p: 0.017) and left S2 (413 vs. 229 µV, p: 0.009) were statistically higher for the NE group. All amplitudes obtained using NEs, except on the left for V1, R1, V2, and R2, were statistically higher than those obtained using ETEs. There was no loss of signal or vocal cord palsy in the patients. There were no needle-related complications. EBSLN monitoring using NE is a safe alternative to ETE. With NE, higher amplitudes were obtained. Level of evidence: Level 3.