Accidental parathyroidectomy as a risk factor for postoperative hypocalcemia in thyroid surgery

Introduction. Hypocalcemia is the most common complication in thyroid surgery. The identification of risk factors is useful to avoid postoperative hypocalcemia and prolonged hospital stay in patients who underwent total thyroidectomy. The aim of this study was to evaluate the impact of accidental parathyroidectomy during thyroidectomy on the postoperative calcemic status of the patients. Materials and Methods. Clinical and pathological data of 102 patients who underwent total thyroidectomy were reviewed. We compared postoperative serum calcium levels of 51 patients without accidental removal of the parathyroids (group A) with those of 51 patients with unintentional parathyroidectomy (group B). Furthermore, calcemic levels were stratified in relation to the number of parathyroids accidentally removed. Results. Biochemical postoperative hypocalcemia was observed in 40 (39%) patients overall: eleven of them belonged to Group A and 29 to Group B. The mean value of postoperative calcemia was 8.5 mg/dL in group A and 7.9 mg/dL in Group B. Patients with one parathyroid excised presented hypocalcemia in 50% of cases, while biochemical hypocalcemia was observed in all patients with more than one gland excised. Conclusions. Our data suggest that unintentional parathyroidectomy during total thyroidectomy increases the incidence of post-operative hypocalcemia. The number of glands accidentally excised influences the incidence rates of postoperative hypocalcemia.