Relationship between the Number of Preserved Parathyroid Glands and Clinical Aspects after Thyroidectomy in PTC

Abstract

Objectives: Identify the relationship between the preservation status of the parathyroid gland and risk of hypoparathyroidism after total thyroidectomy in papillary thyroid carcinoma. Methods: Medical records of 63 patients with papillary thyroid carcinoma who satisfied our inclusion criteria were reviewed retrospectively. Patients with PTC who underwent total thyroidectomy with central lymph node dissection (CLND) were included. Patients were grouped according to the number of intact preserved parathyroid glands into Group 1 (more than four), Group 2 (three), Group 3 (under two). The total and ionized serum calcium, intact parathyroid hormone (PTH) levels of each group were monitored after the surgery. Patients with postoperative symptomatic hypocalcemia were considered to have postoperative hypoparathyroidism and received calcium/vitamin D therapy. The hypoparathyroidism was considered to be permanent when calcium/vitamin D therapy was still required six months after surgery. Results: 31 cases (49.2%) showed postoperative hypoparathyroidism as demonstrated by laboratory findings. Permanent hypoparathyroidism did not occur in this case. The development of hypoparathyroidism was not significantly related with the number of preserved parathyroid glands. Conclusions: To prevent postoperative and permanent hypoparathyroidism following total thyroidectomy, at least two parathyroid glands should be preserved in situ with an intact blood supply. Patients with more extensive CLND procedure did not necessarily show an increased rate of transient hypoparathyroidism. With PTC, the rates of metastasis and recurrence in central lymph nodes are high. Therefore, this study suggests that CLND should be more routinely done for PTC. Hypoparathyroidism can be kept to a minimum by a thorough knowledge of the anatomy and by meticulous hemostasis and delicate surgical technique.