Risk factors of hypoparathyroidism following total thyroidectomy with central lymph node dissection

The risk factors of hypoparathyroidism after total thyroidectomy (TT) with central lymph node dissection (CND) have not been completely defined. The aim of the study was to evaluate the risk factors of hypoparathyroidism after the surgery.We retrospectively reviewed our patients who underwent TT and CND (including lateral lymph node dissection) for thyroid carcinoma between January 2013 and June 2016. According to the postoperative serum levels of parathyroid hormone within 6 months, the patients were divided into normal, transient hypoparathyroidism, and permanent hypoparathyroidism groups. The clinicopathologic characteristics and surgical details were compared among the 3 groups. The risk factors of hypoparathyroidism were investigated by univariate and multivariate analyses.Of the 903 patients, 399 (44.2%) were found to have transient hypoparathyroidism and 10 (1.1%) had permanent hypoparathyroidism. On multivariate analysis, female gender (P < .001), nonuse of carbon nanoparticles (P = .038), parathyroid autotransplantation (P < .001), accidental parathyroid resection (P = .004), and bilateral CND (BCND, P = .003) were the independent risk factors of transient hypoparathyroidism; nonuse of carbon nanoparticles (P = .041) and a tumor in the upper pole of thyroid gland (P = .031) were the independent risk factors of permanent hypoparathyroidism. Patients with transient hypoparathyroidism were more likely to develop permanent hypoparathyroidism when they had hypertension (P = .026) and a tumor in the upper pole of thyroid gland (P = .010).Precise surgical techniques and carbon nanoparticles suspension should be applied for in situ preservation of parathyroid glands (PGs) in thyroid carcinoma patients, especially in females with hypertension and a tumor in the upper pole of thyroid gland. Autotransplantation is only performed when a PG is resected inadvertently or devascularized. TT with BCND should be better performed by an experienced surgeon to reduce the incidence of hypoparathyroidism.