Recovery of severely damaged parathyroid function after total thyroidectomy for thyroid cancer.

Background An extremely low parathyroid hormone (PTH) concentration after thyroidectomy may reflect the immediate severely damaged parathyroid function. The current study aimed to examine time-related changes of severely damaged parathyroid function on postoperative day 1 (SDPF-D1), which was here defined as serum PTH ≤1 pg/mL, and the risk factors of SDPF-D1. Methods This is a retrospective review of patients with thyroid cancer undergoing total thyroidectomy with or without central neck dissection (CND). The number of parathyroids preserved in situ, autotransplanted, or found in the final pathology was recorded and the corresponding parathyroid glands remaining in situ (PGRIS) score (PGRIS = 4 - parathyroids autotransplanted-parathyroids found in the final pathology) was calculated. Chronological changes of serum levels of PTH and total calcium were investigated for at least one year after surgery. Results One hundred and twenty-two of 344 patients included for analysis suffered from SDPF-D1. Patients with SDPF-D1 had a prolonged recovery in comparison with hypoparathyroidism patients without SDPF-D1, who fully recovered within 6 months after thyroidectomy. The PGRIS score in patients with permanent hypoparathyroidism was significantly lower than other patients with SDPF-D1who fully recovered. Conclusions Most patients with SDPF-D1 could fully recover within one year after total thyroidectomy. Less parathyroids removed and autotransplanted contributed to a quick recovery of SDPF-D1.