The influence of intraoperative parathyroid hormone monitoring on the surgical management of hyperparathyroidism

Objective: To examine the role of intraoperative rapid parathyroid hormone (PTH) monitoring in the surgical management of hyperparathyroidism. Design: Thirty-eight-month retrospective review. Setting: Tertiary care academic medical center. Patients: One hundred consecutive patients undergoing surgery for primary h yperparathyroidism. Intervention: All patients underwent preoperative technetium Tc 99m sestami bi scan localization and intraoperative blood PTH monitoring by means of a rapid (12-minute) immunochemiluminometric assay. Main Outcome Measures: The influence of intraoperative PTH levels on extent of surgical dissection and achievement of postoperative normocalcemia. Results: Intraoperative PTH levels dropped an average of 64%, 75%, and 83% at 5, 10, and 20 minutes, respectively, after excision of all hyperfunction ing parathyroid tissue. A PTH decrease of 46% or more at 10 minutes and 59% or more at 20 minutes after excision of hyperfunctioning tissue was predic tive of postoperative normocalcemia. In 79 patients (79%), the sestamibi sc an provided accurate preoperative localization; all but 1 of these patients were treated successfully, most often with a limited, gland-specific disse ction. In 24 patients with inaccurate, negative, or misleading preoperative sestamibi scans, 23 (96%) were treated successfully with the use of the in traoperative PTH assay. Conclusions: The rapid intraoperative PTH assay accurately predicts postope rative success in patients with primary hyperparathyroidism. The rapid PTH assay allows for greater confidence in performing limited dissections in we ll-localized uniglandular disease. In cases of inaccurate preoperative loca lization, the rapid PTH assay directly affects surgical decision making and provides greater confidence in determining when surgical success has been achieved.