Intra-operative vagal neuromonitoring predicts non-recurrent laryngeal nerves: technical notes and review of the recent literature.

BACKGROUND: During thyroid surgery, extreme caution must be taken not to harm the recurrent laryngeal nerve to avoid vocal cord palsy. A non-recurrent laryngeal nerve (NRLN) is a rare anatomical variation that is extremely vulnerable during thyroid surgery. METHODS: Description of two NRLN during thyroid surgery discovered early by using continuous intra-operative vagal nerve neuromonitoring and review of the literature. RESULTS: During thyroid surgery, we use continuous intra-operative vagal nerve neuromonitoring starting with checking vagal nerve signals. It is essential to start stimulation in the most proximal portion of the carotid sheath. An absent pre-dissection signal on the right vagal nerve with a positive signal on the left vagal nerve indicates a non-recurrent course of the right laryngeal nerve. Post-operatively computed tomography scan (CT-scan) was performed and showed an associated extra-anatomical course of the subclavian artery also known as an arteria lusoria. CONCLUSION: The NRLN is an important surgical challenge because unilateral palsy can lead to permanent hoarseness. This anomaly emphasizes the importance of a thorough surgical dissection and the use of intra-operative vagal nerve neuromonitoring. Our method of continuous intra-operative vagal nerve monitoring makes it possible to predict a non-recurrent laryngeal nerve in an early stage during surgery.

Robotic-assisted parathyroidectomy through lateral cervical approach: first results in Belgium.

OBJECTIVE: A parathyroidectomy has been the treatment of choice for primary hyperparathyroidism. Especially the improved imaging techniques have led to minimally invasive techniques. Aim of this study was to evaluate our experience with robot-assisted parathyroidectomy through lateral cervical approach. STUDY DESIGN: Prospective clinical cohort. METHODS: All consecutive patients who underwent a robotic-assisted parathyroidectomy for primary hyperparathyroidism since 2011 were enrolled in this study. Demographic data, biometrics, imaging data and surgery data were collected. Main outcomes were postoperative hypocalcemia, recurrent laryngeal nerve paralysis and other postoperative complications. RESULTS: Twenty-two patients were enrolled. When patients with conversion were excluded (39%) mean operating time was 69 min. In all patients a normal value of serum PTH-levels was achieved 4 h postoperatively. Mean value of serum calcium was 2.92mmol/L preoperative and 2.33mmol/L postoperative. There was no persistent hypocalcemia in any of our patients. 87% was discharged on the first postoperative day. Esthetic results were excellent. CONCLUSIONS: Robotic-assisted parathyroidectomy through lateral cervical approach is a safe and feasible procedure in patients with posteriorly localized parathyroid adenomas. Preoperative imaging techniques are crucial to detect the exact location.

New placement of recording electrodes on the thyroid cartilage in intra-operative neuromonitoring during thyroid surgery.

OBJECTIVE: During thyroid surgery, extreme caution is needed not to harm the recurrent laryngeal nerve and to avoid vocal cord palsy. Intra-operative neuromonitoring became increasingly popular as an adjunct to the gold standard of visual identification of the recurrent laryngeal nerve (RLN). Electromyographic (EMG) responses are normally recorded by electrodes attached to the endotracheal tube. Alteration in position can lead to false loss of signal. We developed thyroid cartilage electrodes that can be fixed directly onto the thyroid cartilage. STUDY DESIGN: Prospective clinical cohort METHODS: Thyroid surgery with intra-operative neuromonitoring using both endotracheal tube-based electrodes and thyroid cartilage electrodes was performed in 25 patients undergoing thyroid surgery. EMG data were collected and reported as median and interquartile ranges (IQR), and the results were compared with the x Wilcoxon signed-rank test for paired measurements. RESULTS: After stimulating vagal nerve (VN), recurrent laryngeal nerve (RLN) and external branch of the superior laryngeal nerve (EBSLN), significantly higher EMG amplitudes were measured before and after thyroid resection for the thyroid cartilage (TC) electrodes, in all comparisons except for the right VN. At the level of the left EBSLN, median amplitude of 560 mV (IQR 190-1050) before and 785 mV (IQR 405-3670) after resection was noted. At the level of the right EBSLN, median amplitude of 425 µV (IQR 257-698) before and 668 mV (IQR 310-1425) after resection was noted. Median amplitudes of 760 mV (IQR 440-1180) and 830 mV (IQR 480-1490) were noted at the left RLN, median amplitudes of 695 mV (IQR 405-1592) and 1078 mV (IQR 434-1895) were noted at the right RLN. CONCLUSION: Thyroid cartilage electrodes appear to be a feasible and reliable alternative for endotracheal electrodes.