Usefulness of intraoperative parathyroid hormone measurements in patients with renal hyperparathyroidism

Background In renal hyperparathyroidism, it remains unclear whether intraoperative parathyroid hormone (PTH) measurements can predict postoperative outcome and guide the extent of surgical exploration. Methods In 42 parathyroidectomies for renal hyperparathyroidism, we analyzed the predictive value of the Miami Criterion of 50% intraoperative PTH decrease. We used receiver operating characteristic (ROC) curves to find the criterion with the best diagnostic performance. We also investigated whether the whole PTH assay improved accuracy. Results Twenty-six operations (62%) resulted in normal postoperative PTH. With the Miami Criterion, cure was predicted with a sensitivity of 95% and specificity of only 8%. Specificity could be improved to 50% using a 70% PTH decrease as cut-off level. The whole PTH assay did not improve accuracy. Conclusion Prediction of cure after parathyroidectomy for renal hyperparathyroidism might be improved with a criterion of 70% PTH decrease 10 minutes after excision of all parathyroid glands. Prospective analysis needs to validate this new criterion.