Intraoperative Identification and Preservation of a Right Non-Recurrent Laryngeal Nerve during Thyroidectomy: A Case Report

Abstract

Introduction: Non-recurrent laryngeal nerve (NRLN) is an extremely rare variant of recurrent laryngeal nerve (RLN) or infe-rior laryngeal nerve. It occurs in about 0.3-0.8% on right-side and rarely on left-sided. Being unusual in its course, it is high-ly predisposed to unintentional intraoperative trauma during thyroid surgeries. The preoperative diagnosis could be sug-gested on ultrasound or contrast enhanced Computed Tomography (CT) scan by the presence of aberrant right subclavian artery; but usually the NRLN is identified in the operating room. 
Discussion: This case presents a report of a 44 year-old patient, with symptomatic right sided multinodular goiter treated with right thyroid lobectomy and isthmusectomy. The patient underwent preoperative ultrasonographic and indirect laryn-goscopic examination showing intact function of the vocal cords. During intra-operative dissection, the RLN was not identi-fied in the usual tracheoesophageal groove. Further careful exploration revealed a right sided type 2A NRLN arising straight from Vagus nerve and moving towards larynx. The nerve was carefully identified, preserved and protected throughout the procedure. The patient had no post-operative complications, including no vocal cords dysfunction after the procedure. 
Conclusion: This case highlights the necessity of keeping in mind the possibility of NRLN in the absence of RLN in its ex-pected anatomical course. Anatomical identification of this variation of RLN is important to prevent iatrogenic nerve injury and improve postoperative outcomes.