Efficacy of Transcartilaginous Electrodes for Intraoperative Neural Monitoring During Thyroid Surgery

Abstract

Objectives. This study was conducted evaluate the efficacy of electromyography (EMG) using transcartilaginous (TC) electrodes through the thyroid cartilage and perichondrium.Methods. We prospectively collected EMG data from intraoperative neuromonitoring (IONM) of 54 nerves at risk in 38 patients during thyroidectomy. We followed standardized IONM procedures in all operations. EMG signals from both endotracheal tube (ET) electrodes and TC needle electrodes were recorded simultaneously. We compared the characteristics of the EMG signals and the efficacy of both methods.Results. Significantly higher mean EMG amplitudes were recorded by TC electrodes than by ET electrodes in all four-step procedures (V1-R1-R2-V2, <i>P</i><0.001). Loss of signal (LOS) occurred in five patients in ET electrodes, but in only two patients in TC electrodes. Postoperative laryngoscopy revealed recurrent laryngeal nerve palsy in the two patients who showed LOS from both the ET and TC electrodes, and vocal cord movement was intact in the other three patients. Therefore, the positive predictive values of LOS in ET and TC electrodes were 40% and 100%, respectively.Conclusion. EMG recording using TC needle electrodes is feasible and effective, making it a good alternative technique for IONM.

Laryngeal Neural Monitoring during Pediatric Thyroid Cancer Surgery—Is Transcartilage Recording a Preferable Method?

“…Therefore, alternative methods such as TC-IONM have been studied in recent years to minimize factors that negatively affect ET-IONM accuracy and efficacy [23][24][25][26][27][28][29][30][31].…”

“…In experimental studies, Wu et al [24] confirmed the hypothesis that transcartilage (TC) recording electrodes can function like the ET-based electrodes and enable access to the EMG response of the vocalis muscle originating from the thyroid cartilage inner surface. Recent clinical studies have further confirmed that, in adult thyroid surgery, TC-IONM provides significantly higher signal strength and stability and significantly less false signal compared to ET-IONM [25,26]. Therefore, TC-IONM is increasingly recognized as an acceptable alternative to ET-IONM and is gradually expanding to other aspects of thyroid surgery [27][28][29][30][31][32].…”

New Developments in Anterior Laryngeal Recording Technique During Neuromonitored Thyroid and Parathyroid Surgery

“…Regarding the basis of anatomy, there are many innovative hypotheses and possible solutions including novel electrodes designs have been proposed. For example, many experimental (14)(15)(16)(17)(18) and clinical studies (19)(20)(21)(22)(23)(24)(25)(26)(27)(28) have confirmed the hypothesis that needle or adhesive surface recording electrodes attached to the thyroid cartilage (transcartilage or percutaneous recordings) or attached to the overlying neck skin (transcutaneous recording) can function like ET electrodes by enabling access to the EMG response of the vocal fold muscles (vocalis muscle and thyroarytenoid muscle) originating from the inner TC surface (Table 1, Figure 1). These studies have also demonstrated that transcutaneous or transcartilage anterior laryngeal (AL) recording electrodes are as accurate as ET-based surface electrodes in depicting RLN stress during IONM.…”

Success rate and learning curve of intraoperative neural monitoring of the external branch of the superior laryngeal nerve in thyroidectomy

“…We routinely confirmed the proper placement of the EMG tube using flexible fiberoptic laryngoscopy after extension of the neck and patient positioning. 3,4,21 A nerve integrity monitoring (NIM)-response 3.0 system (Medtronic, Jacksonville, FL, USA) with the standard EMG tube or a C2 nerve monitor system (Inomed, Teningen, Germany) was used for neuromonitoring based on availability. We used surgical loupes to identify the EBSLN routinely.…”