Clinicopathological characteristics and predisposing risk factors of hypoparathyroidism after total thyroidectomy for thyroid cancer

Objective To evaluate clinicopathological characteristics and predisposing risk factors of postoperative hypoparathyroidism after total thyroidectomy for thyroid cancer. Methods This is a retrospective analysis on 539 consecutive total thyroidectomy cases with or without central compartment lymph node dissection for thyroid cancer operated from July 2003 to December 2015. The clinical and pathological features that related to postoperative hypoparathyroidism were studied by χ2 test and multivariate Logistic regression analysis. Results Among the 539 patients, postoperative hypoparathyroidism occurred in 138 patients (25.6%). Univariate analysis found the following risk factors: age <45 years, tumor size ≥1.5 cm, lymph node metastasis, parathyroid autotransplantation, total thyroidectomy plus bilateral central compartment lymph node dissection, thyroidectomy combined modified radical neck dissection, incidental parathyroidectomy, iPTH levels ≤5.8 pg/ml on postoperative day 1 (all P<0.05). Multivariate analysis showed that parathyroid autotransplantation (OR=1.890, 95% CI: 1.297-2.754, P=0.001), total thyroidectomy plus bilateral central compartment lymph node dissection (OR=2.185, 95% CI: 1.475-3.237, P<0.001), incidental parathyroidectomy (OR=2.831, 95% CI: 1.402-3.191, P<0.001), iPTH levels≤5.8 pg/ml on postoperative day 1 (OR=2.323, 95% CI: 1.588-3.399, P<0.001) were independent risk factors. Conclusions Total thyroidectomy plus bilateral central compartment lymph node dissection was associated with an increased risk for postoperative hypoparathyroidism in patients with thyroid cancer. Key words: Thyroidectomy; Hypoparathyroidism; Thyroid neoplasms; Central compartment lymph node dissection; Risk factor