Non-recurrent inferior laryngeal nerve in thyroid surgery: report of three cases and review of the literature

The non-recurrent inferior laryngeal nerve (NRILN) is a nerve anomaly that can be associated with an increased risk of vocal fold paralysis. The purpose of this study was to report three new cases of this anomaly, underline the necessity of recognizing its possibility for the prevention of intra-operative nerve damage and a review of the literature. Three cases of thyroid surgery associated with right NRILN are reported. Two patients underwent bilateral thyroidectomy for a multinodular goitre and for a toxic multinodular goitre respectively. The third patient had a right lobectomy and isthmectomy for a thyroid nodule. All patients had identification of the recurrent laryngeal nerve on the left side and NRILN on the right side. The diagnosis of the NRILN was made per-operatively on all cases. A post-operative computed tomography (CT) scan in two patients, showed a retrooesophageal aberrant right subclavian artery. Post-operatively, all patients had normal vocal fold function on laryngoscopy. The NRILN is a rare anomaly but overlooking its possibility may lead to severe operative morbidity. This is an additional argument in favour of systematic dissection of the recurrent inferior laryngeal nerve during thyroid surgery.