Is the Number of Parathyroid Glands Identified During Total Thyroidectomy a Real Predictive Factor of Postoperative Hypocalcemia?

Abstract

Hypocalcemia after thyroid surgery is a common clinical consequence of thyroidectomy. Between January and June 2007, 116 patients underwent total thyroidectomy. We considered age, sex, thyroid disease (neoplastic or not), the number of parathyroid glands identified during surgery, and mean operative time. Eighty-eight cases were included in the study (age, 56 ± 15 years). Patients were divided in groups according to preoperative diagnosis. Preoperative serum and ionized calcium levels (9 ± 0.4 mg/dL, 1.1 ± 0.1 mmol/L) were compared with postoperative concentration (8.1 ± 0.5 mg/dL, 1.0 ± mmol/L). t Test for nonpaired data was P = 0.008 and t test for paired data was P < 0.0001. Hypocalcemia was present in 34.1% of cases. The number of parathyroids identified during surgery was 2.9 ± 0.6 and 2.3 ± 0.7 (P = 0.0002) in the 2 groups. The incidence of hypocalcemia decreased with the increased number of glands preserved higher than 2 (P = 0.0017). Identification and preservation of 2 or more parathyroid glands during surgery is a helpful predictive risk factor for postoperative hypocalcemia.