Hypoparathyroidism Risk After Total Endoscopic Thyroidectomy for Papillary Thyroid Cancer: A Comparison of the Transoral Vestibular and Breast Approaches

BACKGROUND: This study aimed to compare the risk of hypoparathyroidism between the transoral vestibular approach (TOVA) and the breast approach (BA) in patients undergoing total endoscopic thyroidectomy (TET) for papillary thyroid carcinoma (PTC). METHODS: The medical records of 121 PTC patients (all women) who underwent total TET from January 2015 to January 2021 were retrospectively analyzed. Patients were grouped according to surgical approach (BA or TOVA). Clinical status and concentrations of parathyroid hormone (PTH) and calcium were monitored in the perioperative period and 1, 6, and 12 months after surgery. RESULTS: The BA and TOVA groups comprised 101 and 20 patients, respectively. Clinicopathologic and characteristics and surgical data were comparable between the groups. Incidence of transient hypoparathyroidism was significantly lower in the TOVA group than the BA group (10% vs 63.4%; p <0.01). Incidence of permanent hypoparathyroidism was comparable (5% vs 6.9%). Two days after TET, mean PTH concentration was significantly higher and incidence of abnormal PTH was significantly lower in the TOVA group. The incidence of abnormal calcium concentration 2 days after surgery was significantly lower in the TOVA group. One month after surgery, the mean calcium concentration was significantly higher in the TOVA group. Univariate and multivariate Cox regression analysis suggested that patients who underwent TOVA had a lower risk of transient hypoparathyroidism (hazard ratio 0.05, 95% confidence interval, 0.01–0.23; p<0.01). No clinicopathological factors examined were significantly associated with permanent hypoparathyroidism. CONCLUSION: In patients undergoing TET for PTC, the incidence of transient hypoparathyroidism may be lower with the TOVA than the BA. Surgeons should be aware of the relatively high risk of transient hypoparathyroidism when performing the BA.