Identification of a right-sided nonrecurrent laryngeal nerve during total thyroidectomy using intraoperative nerve monitoring: A lesson in surgical safety

ABSTRACT The recurrent laryngeal nerve (RLN) is a critical structure during thyroidectomy. A rare anomaly, the non-RLN (NRLN), poses a significant surgical risk due to its unpredictable course. Injury to this variant may result in permanent vocal cord dysfunction. Intraoperative nerve monitoring (IONM) facilitates real-time identification and functional confirmation of such variants, enhancing surgical safety. We report the case of a 47-year-old woman who underwent total thyroidectomy for a symptomatic multinodular goiter. During dissection on the right side, the RLN was not identified in its usual tracheoesophageal groove. Using IONM, a transverse branch arising from the vagus nerve directly into the larynx was identified, consistent with a NRLN. The nerve was preserved with the aid of IONM, and the patient recovered uneventfully with normal postoperative vocal cord function. IONM is invaluable in detecting rare anatomical variants such as the NRLN. Awareness of this anomaly and careful dissection guided by IONM are key to preventing nerve injury and postoperative complications.