Identifying the Non-recurrent Laryngeal Nerve: Preventing a Major Risk of Morbidity During Thyroidectomy
A 26-year-old Caucasian woman was referred to the Head and Neck surgery outpatient clinic at Imam Khomeini training Hospital in Urmia. Two years ago, she was noticed to have a cervical mass on the right side. A thyroid nodule was diagnosed and followed-up by a physician, but subsequently, the nodule was enlarged rapidly since five months, so she was referred to the endocrinologist. A fine needle aspiration (FNA) puncture was performed and the result was compatible with thyroid papillary cell carcinoma, then she was referred to the surgeon. She had no surgical history before. She was received medical therapy with levothyroxin for a while, but the preoperative thyroid function tests, all of them were in normal ranges. His physical examination was unremarkable and only a firm three to four cm nodule was palpated in the right lobe of thyroid without any adhesion to the environment. No other enlarged mass or lymphadenopathy was observed in the neck in the first exam in the surgery clinic.\nAccording to the result of FNA, the surgeon decided that she should undergo total thyroidectomy, which was the 270th thyroidectomy of the surgeon.\nUnder general endotracheal anesthesia, a three to five inch low collar incision is made perpendicular to the length of the neck and carried down through the subcutaneous tissue and platysma muscle. Superior and inferior subplatysmal flaps were developed and the strap muscles are divided vertically in the midline and retracted laterally.\nThe skin and subcutaneous tissue was dissected and the thyroid gland and blood vessels were exposed. Blood supply to the thyroid gland was clamped off and ligated by two 2-0 and 3-0 silk sutures.\nFirst, the left lobe of thyroid was resected in association with isthmus. Then the right lobectomy was done by dissecting the superior peduncle of the right lobe.\nThe right inferior thyroid artery was identified. Careful dissection was done to find the right recurrent laryngeal nerve in the area between inferior thyroid artery and mid-cervical (mid-tracheal) line, but despite diligent dissection, no recurrent nerve was observed.\nSo with suspect to have the anatomical variation (non-recurrent laryngeal nerve), the area above the inferior thyroid artery was dissected. The inferior laryngeal nerve usually penetrates the cricothyroid muscle to enter the larynx. The nerve was founded where penetrating the cricothyroid muscle and was followed in a retrograde manner [].\nThe nerve emanated from the right vagus nerve and entered the larynx three to four cm after its origin without showing any recurrent course. The left recurrent laryngeal nerve was observed too, and it was in normal recurrent fashion.\nThe surgery and postoperative period was uneventful and no change on the voice of patient (any hoarseness) was observed.\nGiven the invariably association of NRLN with vascular abnormality (right clavian artery originated directly from the aortic arch), the computerized tomography (CT) angiography imaging was performed which confirmed the presence of vascular anomaly []. Because of being asymptomatic, as usual, no extra measure was considered in this regard.