Preoperative CT diagnosis of aberrant right subclavian artery and prediction of a nonrecurrent laryngeal nerve: a case report.

Introduction: The nonrecurrent laryngeal nerve (NRLN) is a rare anomaly associated with an aberrant right subclavian artery (ARSA). Preoperative recognition is critical to prevent injury during thyroid surgery. Case presentation: A 24-year-old male presented with a right neck mass. Preoperative contrast-enhanced CT revealed ARSA originating from the aortic arch and passing behind the esophagus, suggesting a right NRLN. During endoscopic bilateral total thyroidectomy via a breast approach (ETBA), a Type I NRLN (Toniato) was identified originating directly from the cervical vagus and entering the larynx laterally; it was preserved intact. The patient recovered uneventfully, with normal vocal function at discharge and throughout 14 months of follow-up. Discussion: CT detection of an ARSA should alert surgeons to the possibility of an NRLN, guiding intraoperative dissection away from the tracheoesophageal groove toward the vagal trunk. Conclusion: Preoperative CT is a valuable tool for predicting NRLN. Surgeons should remain vigilant when ARSA is present to enable early nerve identification and preservation.