English

Abstract

Both the cases discussed here had right sided NRLN, out of which one had associated aberrant right subclavian artery. None had iatrogenic nerve palsy. Dissection was difficult as during the routine procedure of dissection, the nerve was not found in its usual route and was found that the right laryngeal nerve was not recurrent and originated directly from the vagus nerve. The non-recurrent laryngeal nerve (NRLN) is a rare embryologically derived variant of the recurrent laryngeal nerve and is found in 0.25 to 0.99% of patients who undergo thyroid surgery. On the right side, NRLN is found in 0.3% to 0.8% of patients and it is extremely rare on the left (0.004%).[1-2] The right NRLN is found to be associated with an aberrant right subclavian artery (86.7%) In experienced hands, meticulous dissection in the region of the tracheoesophageal groove will result in identification of RLN. In any case, if the nerve is not seen / found longitudinally along the tracheoesophageal groove, then dissecting transversely along the fascial spaces between the carotid sheath and the larynx, will allow identification of the presence of NRLN. Recurrent laryngeal nerve is a branch of the vagus nerve that is associated with both motor function and sensation of the larynx. It supplies all the intrinsic muscles of the larynx except the cricothyroid muscles. The non-recurrent laryngeal nerve (NRLN) is a rare embryologically derived variant of the recurrent laryngeal nerve and occurs in 0.25 to 0.99% of patients who undergo thyroid surgery and was first reported by Steadman in 1823.[3] on the right side, NRLN is found in 0.3% to 0.8% of patients and on the left side, it is extremely rare (0.004%).[1-2] The right NRLN is found to be associated with an aberrant right subclavian artery (86.7%).[1],[4] The NRLN is usually an unexpected surgical discovery, specifically during thyroidectomy. Hence, adequate anatomic knowledge of the normal course and variations/types of NRLN, and careful dissection during surgery is necessary to prevent iatrogenic injury to the nerve. We are reporting two cases of NRLN, which were identified while performing total thyroidectomy in patients diagnosed with papillary ca thyroid.