Is systematic identification of all four parathyroid glands necessary during total thyroidectomy?: a prospective study.

OBJECTIVES/HYPOTHESIS Routine identification of all four parathyroid glands has been advocated as a means of reducing rates of postoperative hypocalcemia and inadvertent parathyroidectomy. The object of the present study was to investigate whether identification of more parathyroid glands during thyroidectomy performed by capsular dissection technique had any impact on incidence of postoperative hypocalcemia and unintentional parathyroid resection. STUDY DESIGN Prospective cohort study of consecutive patients undergoing total thyroidectomy by capsular dissection technique over a 3-year period. Exclusion criteria included performance of concomitant central neck dissection, hyperparathyroidism, revision surgery, and invasive cancer. METHODS The number of parathyroid glands identified intraoperatively was recorded. No effort was made to find glands that were not obviously apparent during the course of dissection. Patients were not placed on routine calcium supplementation. RESULTS The final study population consisted of 126 patients. The mean number of parathyroid glands identified was 2.3. The incidence of biochemical (any postoperative calcium <2 mmol/L) and clinical hypocalcemia was 22.2% and 10.3%, respectively. Patients in group A (0-2 parathyroids identified) had a significantly lower incidence of clinical hypocalcemia than patients in group B (3-4 parathyroids identified) (3.2% vs. 17.1%, P = .02). The differences in biochemical hypocalcemia were not significant (16.1% vs. 28.1%, P = .13). The incidence of inadvertent parathyroidectomy was 9.5%. There was no difference between the groups in incidence of inadvertent parathyroidectomy (9.7% vs. 9.4%, P = 1.0). CONCLUSIONS Routine identification of all four parathyroid glands is not necessary in thyroidectomy performed using capsular dissection technique.