Noninvasive monitoring of the vagus nerve during thyroid surgery using cutaneous adhesive and needle electrodes: What is the optimal configuration?

• Published in: Head & neck Vol. 46; no. 8; pp. 1893 - 1901
• Main Authors: Karcioglu, Amanda Silver, Trinh, Lily N., Mcllroy, Dioan, Okose, Okenwa C., Wang, Bo, Behr, Ian J., Cheung, Anthony Y., Srikanthan, Adithya, Russell, Marika D., Kamani, Dipti, Abdelhamid Ahmed, Amr H., Randolph, Gregory W.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01-08-2024; Wiley Subscription Services, Inc
• Subjects: Adhesives; Anesthesia; cutaneous surface electrode; Electrodes; Electromyography; Feet; intraoperative neuromonitoring; Parathyroid; recurrent laryngeal nerve; Superior laryngeal nerve; Surgery; Thyroid; Thyroid gland; thyroid surgery; Vagus nerve; intraoperative neuromonitoring; vagus nerve; cutaneous surface electrode; recurrent laryngeal nerve; thyroid surgery
• ISSN: 1043-3074; 1097-0347; 1097-0347
• DOI: 10.1002/hed.27669

Objective
Endotracheal tube (ETT) surface electrodes are used to monitor the vagus nerve (VN), recurrent laryngeal nerve (RLN), and external branch of the superior laryngeal nerve (EBSLN) during thyroid and parathyroid surgery. Alternative nerve monitoring methods are desirable when intubation under general anesthesia is not desirable or possible. In this pilot study, we compared the performance of standard ETT electrodes to four different noninvasive cutaneous recording electrode types (two adhesive electrodes and two needle electrodes) in three different orientations.
Methods
The VN was stimulated directly during thyroid and parathyroid surgery using a Prass stimulator probe. Electromyographic (EMG) responses for each patient were recorded using an ETT plus one of the following four cutaneous electrode types: large‐foot adhesive, small‐foot adhesive, long‐needle and short‐needle. Each of the four electrode types was placed in three orientations: (1) bilateral, (2) ipsilateral mediolateral, and (3) ipsilateral craniocaudal.
Results
Four surgical cases were utilized for data collection with the repetitive measures obtained in each subject. Bilateral electrode orientation was superior to ipsilateral craniocaudal and ipsilateral mediolateral orientations. Regardless of electrodes type, all amplitudes in the bilateral orientation were >100 μV. When placed bilaterally, the small‐foot adhesive and the long‐needle electrodes obtained the highest EMG amplitudes as a percentage of ETT amplitudes.
Conclusion
Cutaneous electrodes could potentially be used to monitor the VN during thyroid and parathyroid procedures. Different electrode types vary in their ability to record amplitudes and latencies. Bilateral orientation improves EMG responses in all electrode types. Additional validation of cutaneous electrodes as an alternative noninvasive method to monitor the VN is needed.