Inadvertent parathyroidectomy during thyroid surgery: the incidence of a complication of thyroidectomy

Incidental parathyroidectomy is a complication of thyroid surgery. The aim of this report is to explore the incidence, risk factors, and clinical relevance of inadvertent parathyroidectomy during thyroidectomy.

Patients who underwent thyroidectomy between January 1998 and June 2005 were evaluated. Pathology reports were reviewed for the presence of parathyroid tissue in the thyroidectomy specimens. Information regarding diagnosis, operative details, and postoperative hypocalcemia were collected.

Three hundred and fifteen thyroid procedures were performed: 163 total thyroidectomies, 124 near-total thyroidectomies, and 28 lobectomies. The findings were benign in 240 and malignant in 75 cases. Incidental parathyroidectomy was found in 68 (21.6%) cases: 58 were benign and 10 were malignant. One and two parathyroids were accidentally removed in 46 and 22 patients, respectively. Parathyroid tissue was found in intrathyroidal (33%) and extracapsular (27%) sites. Total/near-total thyroidectomy was not associated with increased risk of incidental parathyroidectomy (P=0.646), and there was no association of inadvertent parathyroidectomy with postoperative hypocalcemia (P=0.859). Thyroid malignancy was associated with decreased incidence of incidental parathyroidectomy (P=0.047).

Inadvertent parathyroidectomy, although not uncommon, is not associated with postoperative hypocalcemia. The type of surgical procedure does not increase the risk of incidental parathyroidectomy, while thyroid malignancy may reduce the incidence of inadvertent parathyroidectomy.