Intraoperative decay profile of intact (1-84) parathyroid hormone in surgery for renal hyperparathyroidism - A consecutive series of 80 patients

Background. The utility of intraoperative parathyroid hormone (PTH) monitoring is unclear in the surgical management of renal hyperparathyroidism. Our goal was to define the normal pattern of decay during operation for renal hyperparathyroidism by using the rapid intact (1-84) parathyroid hormone (PTH) assay. Methods. Eighty consecutive patients underwent neck exploration for renal hyperparathyroidism. Intact PTH levels were monitored with a rapid immunochemiluminometric assay. Samples were assayed at the induction of anesthesia, after dissection before resection, and 20 and 40 minutes after resection. Follow-up ranged from 3 to 24 months. Results. Twenty minutes after resection, PTH levels remained many-fold supranormal. Seventy-seven patients (96%) were cured. Of these, 75 patients (94%) had PTH decay of more than 50% from the preoperative level; 74 (99%) were cured. Only 1 of 3 patients (33%) in whom the PTH level decreased less than 40% from the preoperative level was cured. Two patients had intermediate values and both were cured. Conclusions. The intraoperative decay of PTH during operation for renal hyperparathyroidism is slower than for patients with normal renal function. However, 20 minutes after resection, a decline to less than 50% of the preoperative level predicts cure, while a level greater than 60% predicts failure.