Aim:

Bilateral total thyroidectomy is performed for the treatment of multinodular goiter, thyroid cancer and hyperthyroidism. Hypocalcemia is the most common complication seen after operation and may be transient or permanent. The aim of our study was to reveal the factors associated with hypocalcemia after surgery and measures that can be taken for the prevention of hypocalcemia.

Methods:

We retrospectively evaluated records of patients who underwent total thyroidectomy between January 2013 and September 2017 in our clinic. Demographic characteristics, thyroid hormone and vitamin D levels, calcium and parathyroid hormone levels before and after surgery, oral or intravenous calcium replacement requirements and length of hospital stay were recorded. Patients who underwent neck dissection and completion surgery and who were operated for hyperthyroidism were excluded.

Results:

A total of 721 patients (576 female and 145 male) were included in the study. The mean postoperative calcium level in females and males was 8.1±0.7 mg/dL and 8.5±0.4 mg/dL, respectively (p=0.001). The mean preoperative vitamin D level in females and males was 13.7±7.3 ng/mL and 8.5±0.4 ng/mL, respectively (p<0.001). The mean postoperative parathyroid hormone level in females and males was 30.7±15 ng/L and 34.8±14.5 ng/L, respectively (p=NS). The mean postoperative parathyroid hormone level and length of hospital stay in hypocalcemic and normocalcemic patients was 37.1±12.5 ng/L and 27.9±15.3 ng/L (p<0.001) and 2.58±1.23 and 2.08±0.5 days, respectively (p=0.001).

Conclusion:

Vitamin D insufficiency, postoperative hypoparathyroidism and female sex were found to be risk factors for postoperative hypocalcemia. Among these risk factors, vitamin D insufficiency can be treated before surgery to prevent this complication.

Keywords: Bilateral total thyroidectomy, hypocalcemia, hypoparathyroidism, vitamin D insufficiency