Intraoperative parathyroid hormone testing improves cure rates in patients undergoing minimally invasive parathyroidectomy.

BACKGROUND: Intraoperative parathyroid hormone (iPTH) testing often is used during minimally invasive parathyroidectomy for primary hyperparathyroidism (1 degrees HPT). However, several investigators report that these assays are not cost effective and do not improve outcomes significantly.

METHODS: To determine the impact of iPTH testing on the outcomes of patients with 1 degrees HPT, we reviewed our experience. From January 1990 to June 2004, there were 345 consecutive patients with 1 degrees HPT and positive localization studies for a single parathyroid adenoma who were candidates for minimally invasive parathyroidectomy. Group 1 patients (n = 157) underwent parathyroid exploration without iPTH testing and group 2 patients (n = 188) had an operation with iPTH testing.

RESULTS: Of the group 1 patients, 15 (10%) still were hypercalcemic postoperatively owing to additional unidentified hyperfunctioning parathyroid glands. In contrast, among 188 group 2 patients, 170 (90%) had resection of a single parathyroid adenoma, a greater than 50% decrease in iPTH levels, and were cured. The remaining 18 (10%) patients did not have an adequate reduction in iPTH levels and underwent bilateral neck exploration with resection of additional parathyroids. Of these 18 patients, 9 had double adenomas and 9 had 3- or 4-gland hyperplasia. Importantly, all patients in group 2 were cured.

CONCLUSIONS: iPTH testing improves cure rates in patients undergoing minimally invasive parathyroidectomy. iPTH testing allowed intraoperative recognition and resection of additional hyperfunctioning parathyroids missed by preoperative imaging studies. Consequently, we strongly advocate the routine use of iPTH testing in patients who undergo minimally invasive parathyroidectomy for 1 degrees HPT.