Risk factors of hypoparathyroidism after bilateral total thyroidectomy Hypoparathyroidism after thyroidectomy

Aim: Hypoparathyroidism (HPP) is a complication after thyroid surgery that is difficult-to-treat in the long term. Our aim was to assess the outcomes of patients undergoing bilateral total thyroidectomy for thyroid disorders and to determine the incidence and risk factors of transient or permanent HPP. Material and Method: The outcomes of patients who underwent bilateral total thyroidectomy were evaluated. The patients were divided into three groups, namely those that did not develop hypocalcemia (Group 1), those that developed transient hypocalcemia (Group 2), and those that developed permanent hypocalcemia (Group 3). Results: The mean postoperative Ca and iPTH levels were 8.1 +/- 0.6 mg/dL and 37.1 +/- 17.8 pg/mL, respectively in Group 1; 7.6 +/- 0.5 mg/dL and 10.9 +/- 10.7 pg/mL, respectively in Group 2; and 7.4 +/- 0.7 mg/dL and 8.2 +/- 9.6 pg/mL, respectively in Group 3. Postoperative Ca and iPTH levels were significantly lower in Group 2 and Group 3 compared to Group 1 (p<0.01). An inter-group analysis with respect to mean excised nodule size revealed a mean nodule size of 20.1 +/- 14.3 mm in Group 1; 21.5 +/- 14.5 mm in Group 2; and 35.6 +/- 11.5 mm in Group 3. The mean excised nodule size of Group 3 was significantly greater than those of the other groups (p<0.05). Discussion: Female gender, low preoperative calcium level, the number of incidentally excised parathyroid glands, and nodule size were considered risk factors for developing postoperative HPP; thus, it is recommended to follow such patients closely in the postoperative period.