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

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.

Surgical and Biochemical Outcomes in Nerve Monitored Reoperation Surgery for Recurrent Papillary Thyroid Carcinoma.

OBJECTIVE: To study the surgical and biochemical outcomes in nerve-monitored reoperation or revision surgery for recurrent thyroid cancers. STUDY DESIGN: A single-center retrospective study. SETTING: Tertiary center. METHODS: We identified patients with recurrent papillary thyroid carcinoma (PTC) who underwent reoperation/revision surgery. Study outcomes were surgical complications frequency, recurrence, distant metastasis, and biological complete response (BCR) by comparing preoperative and postoperative thyroglobulin (Tg) levels. RESULTS: Out of 227 patients, 33.9% presented for ≥2 reoperation surgeries. Nineteen (8.4%) had permanent preoperative hypoparathyroidism while 22 patients (9.7%) had preoperative vocal cord paralysis (VCP). Following reoperation surgery, there were 12 cases (5.3%) of permanent hypocalcemia and no cases of unexpected postoperative VCP. BCR was achieved in 31 patients (35.2%) with complete Tg data. Mean preoperative Tg was 47.7 ng/mL and was 19.7 ng/mL postoperatively (p = .003). The cervical nodal recurrence rate after final surgery was 7.0% (n = 16). CONCLUSION: Reoperation surgery for recurrent PTC may help achieve biochemical remission regardless of age or the number of prior surgeries.

Comparison of Monopolar and Bipolar Stimulator Probes for Intraoperative Nerve Mapping During Thyroidectomy: A Prospective Study.

OBJECTIVES/HYPOTHESIS: During intraoperative neuromonitoring in thyroid surgery, two different kinds of stimulator probes, monopolar and bipolar, are commonly used to stimulate the laryngeal nerves. We explore the unique characteristics of both of these probes as they relate to intraoperative laryngeal nerve mapping. METHODS: Twenty-one patients undergoing neuromonitored thyroidectomy by a single surgeon were enrolled. Electromyography (EMG) amplitude and latency measurements were prospectively recorded concurrently from 1 mA stimulation of vagus nerve (VN) and inferior/superior recurrent laryngeal nerve before (with and without fascia) and after thyroid resection using bipolar and monopolar stimulator probes. RESULTS: Significantly higher amplitudes were obtained with monopolar stimulator probes as compared to bipolar probes, in several stimulation scenarios such as at right VN pre-resection (carotid sheath intact), right VN pre-resection (carotid sheath dissected), right VN post-resection and left VN (carotid sheath dissected). No significant differences were found between amplitudes and latency values in all other stimulation scenarios. CONCLUSIONS: According to this study, both probes are reliable and safe for neural mapping. The kind of probe used during neural monitoring is based on surgical situations and surgeon preference. LEVEL OF EVIDENCE: 3 (According to Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence) Laryngoscope, 131:E2718-E2726, 2021.

Virtual Reality Improves the Patient Experience during Wide-Awake Local Anesthesia No Tourniquet Hand Surgery: A Single-Blind, Randomized, Prospective Study.

Wide-awake local anesthesia no tourniquet surgery has been shown to decrease cost and hospital length of stay. The authors studied the use of virtual reality during wide-awake local anesthesia no tourniquet outpatient upper extremity surgery to assess its effect on patient pain, anxiety and fun. Patients undergoing wide-awake local anesthesia no tourniquet surgery were randomized to use (virtual reality) or not use (non-virtual reality) virtual reality during their procedures. Pain, fun, and anxiety were measured with a Likert scale at several time points, as were blood pressure and heart rate. A postoperative questionnaire was used to assess overall satisfaction. Virtual reality patients exhibited lower anxiety scores during injection, during the procedure, and at the end of the procedure. There were no differences in blood pressure, heart rate, or pain scores. Compared with non-virtual reality patients, virtual reality patients' fun scores were higher. Virtual reality patients felt the experience helped them to relax, and they would recommend virtual reality-assisted wide-awake local anesthesia no tourniquet surgery. Among patients with self-reported preexisting anxiety, virtual reality patients had lower pain and anxiety scores during injection of local anesthesia compared with non-virtual reality patients. This study demonstrates that readily available virtual reality hardware and software can provide a virtual reality experience that reduces patient anxiety both during the injection of local anesthesia and during the surgical procedure. (Plast. Reconstr. Surg. 144: 408, 2019.) CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, II.