Effect of recurrent laryngeal nerve identification technique in thyroidectomy on recurrent laryngeal nerve paralysis and hypoparathyroidism.

OBJECTIVE To investigate whether the recurrent laryngeal nerve (RLN) identification technique used in thyroidectomy affects RLN paralysis and hypoparathyroidism. DESIGN Patients were allocated into 2 groups according to the thyroidectomy technique used to identify the RLN: (1) superior-inferior direction, exploring the nerve where it enters the larynx, followed by superior pedicle ligation; and (2) inferior-superior direction, following the inferior pedicle ligation and identifying the nerve in the tracheoesophageal groove. The first and second groups included 67 and 128 patients, respectively. In the first group, 19 patients underwent lobo-isthmectomy, and 48 underwent total thyroidectomy. In the second group, 42 patients underwent lobo-isthmectomy, and 86 underwent total thyroidectomy. We performed 115 and 214 RLN dissections in the first and second groups, respectively. SETTING Academic tertiary hospital. PATIENTS The study included 195 consecutive patients, 161 female (82.5%), and 34 male (17.5%), who underwent thyroidectomy for goiter between January 2006 and August 2009. Their mean age was 44.7 years (range, 14-79 years). The mean follow-up was 26 months (range, 12-42 months). INTERVENTIONS Unilateral or bilateral total thyroidectomies performed using extracapsular dissection with 2 different RLN identification techniques. MAIN OUTCOME MEASURES Incidence of hypocalcemia, vocal cord paralysis, hemorrhage, and wound infection. RESULTS No RLN paralysis was observed in the first group. In the second group, unilateral RLN paralysis was seen in 2 of 128 patients (1.5%). Groups 1 and 2 included 48 and 86 total thyroidectomies, respectively. Temporary hypoparathyroidism was observed in 4 patients in the first group (8.3%). In the second group, permanent hypoparathyroidism was observed only in 4 patients (4.6%), and temporary hypoparathyroidism was observed in 14 patients (16.2%). CONCLUSIONS Comparing the 2 groups based on the frequencies of RLN paralysis and hypoparathyroidism, we found that complications were significantly lower in the first group (P < .05) in terms of hypoparathyroidism. The rate of hypoparathyroidism was significantly lower in the thyroidectomies that located the RLN using the superior-inferior approach. In our hands, the superior-inferior approach was a safer technique, in terms of avoiding complications.