Identifying and Preserving the Left Non-Recurrent Laryngeal Nerve During Thyroid Surgery Rare Anatomical Variant: A case report and literature review

Abstract

The non-recurrent inferior laryngeal nerve (NRILN) is a rare anatomical variant of the inferior laryngeal nerve (ILN), with left-sided occurrences being exceptionally uncommon. Recognition of this anomaly is critical to prevent iatrogenic nerve injury during thyroid surgery. Right-sided NRILNs are more frequent and are commonly associated with vascular anomalies such as aberrant right subclavian arteries, whereas left-sided NRILNs are exceedingly rare, typically occurring only in the presence of a right-sided aortic arch with an aberrant left subclavian artery. We report the case of a 34-year-old female with a multinodular goiter causing compressive symptoms. Preoperative imaging revealed a right-sided aortic arch with an aberrant left subclavian artery, raising suspicion for a left NRILN. During total thyroidectomy, the left NRILN was identified and preserved. Histopathology confirmed benign multinodular thyroid disease. This case emphasizes the importance of preoperative imaging and intraoperative vigilance in preventing nerve injury when vascular anomalies are present.