Intraoperative Identification of a Non-recurrent Laryngeal Nerve Associated With an Aberrant Right Subclavian Artery During Thyroidectomy: A Case Report

The purpose of this case report is to highlight the clinical relevance of identifying a non-recurrent laryngeal nerve (NRLN), a rare anatomical variant of the inferior laryngeal nerve (ILN), in the context of thyroid surgery. The NRLN is most commonly associated with an aberrant right subclavian artery (arteria lusoria), and its presence significantly increases the risk of nerve injury during cervical procedures due to its atypical course and unexpected location. We report the case of a 48-year-old female patient undergoing total thyroidectomy for multinodular goiter. Preoperative evaluation revealed, on computed tomography, an aberrant right subclavian artery with a retroesophageal course, consistent with an arteria lusoria and suggestive of an NRLN. Intraoperatively, during careful dissection of the right thyroid lobe, the surgical team noted the absence of the recurrent laryngeal nerve (RLN) in its usual tracheoesophageal location. A nerve branch was identified arising directly from the cervical portion of the vagus nerve, coursing transversely towards the larynx, consistent with a right-sided NRLN. Intraoperative neuromonitoring (IONM) was used to confirm the functional integrity of the identified nerve, preventing inadvertent injury. The surgery proceeded without complications, and the patient had an uneventful recovery with no vocal cord dysfunction or signs of nerve injury. Beyond reinforcing the known association between arteria lusoria and NRLN, this case underscores the value of preoperative imaging as a predictive tool for nerve anomalies and highlights the critical role of IONM in identifying and preserving atypical nerve anatomy. Awareness of such variants and a structured intraoperative approach can significantly reduce the risk of iatrogenic nerve injury, informing best practices in thyroid and neck surgery.