Mohsin, Khuzema1; Bamford, Jeremy2; Murcy, Mohammad1; Aslam, Rizwan3; Kandil, Emad1
1 Division of Endocrine and Oncological Surgery, Tulane University School of Medicine, New Orleans, United States
2 Department of Neurosurgery, Tulane University School of Medicine, New Orleans, United States
3 Department of Otolaryngology-Head and Neck Surgery, Tulane University School of Medicine, New Orleans, United States
Background/Purpose: Continuous intraoperative nerve monitoring using automated periodic stimulation (APS) of the vagus nerve (VN) was proposed to recognize early change in function of the recurrent laryngeal nerve (RLN) during thyroid surgery. The purpose of this study was to examine our initial experience using this technology.
Methods: Prospectively collected data were retrospectively reviewed for all patients who underwent thyroid surgery by a single surgeon using APS technology at a single North American institution for a 5-year period. Stretch injury was established by a warning threshold alarm ? 50% reduction in amplitude and/or ? 10% increase in latency. Preoperative and postoperative direct laryngoscopy was performed for all patients.
Results: A total of 455 RLNs were at risk in 344 consecutive patients. APS alarm detected impending stretch nerve injury in 33 (9.59%) cases by 63.32 ± 13.39 % decrease in amplitude and by 27.3% increase in latency in one case. A total loss of signal (LOS) has been detected in 15 (4.36%) cases. The early change of management by releasing the causative retraction for an average of 2 ± 0.7 minutes successfully preserved the nerves in all cases with impending injury; however, there was no improvement in the LOS cases. Other than the cases with LOS, postoperative laryngoscopy showed normal vocal cord function in all cases.
Discussion & Conclusions: APS technology is safe, feasible and can help in early recognition of intraoperative RLN stretch. Future studies are warranted to further examine the benefits of this technology.
- Yang, S., et al., Systematic review with meta-analysis of intraoperative neuromonitoring during thyroidectomy. Int J Surg, 2017. 39: p. 104-113.
- Schneider, Rick et al. “Continuous Intraoperative Neural Monitoring of the Recurrent Nerves in Thyroid Surgery: A Quantum Leap in Technology.” Gland Surgery 5.6 (2016): 607–616. PMC. Web. 27 Feb. 2017.