Initial Experience with Intraoperative PTH Determinations in the Surgical Management of 130 Consecutive Cases of Primary Hyperparathyroidism

Background: Successful surgical management of primary hyperparathyroidism (1 degree HPT) historically has required bilateral neck exploration. The intraoperative parathyroid hormone (IO-PTH) assay allows a more limited procedure by confirming complete removal of hypersecreting tissue.

Methods: Plasma samples were obtained from 130 consecutive patients both before (preincision and preexcision baselines) and at approximately 5 and 10 minutes (and additional times) after removal of abnormal parathyroid tissue. Samples were assayed for IO-PTH by a rapid, two-site immunochemiluminescent assay (ICMA) with a 7-minute incubation at 45 degrees C.

Results: Plasma IO-PTH decreased by at least 50% in 126 of 130 cases; however, three of these cases were false positives. The four cases in which IO-PTH fell < 50% were classified as two true negatives and two false negatives. A single adenoma was removed in 125 cases, and two or three hyperplastic glands were removed in five cases.

Conclusions: IO-PTH predicted the postoperative outcome in 125 of 130 cases (96.2%), including two of five cases in which multiple hyperplastic glands were removed, and 1 degree HPT was successfully treated in 97.7% (127/130) of the cases. The IO-PTH procedure can provide valuable confirmation to the endocrine surgeon; however, other sources of information must also be used to ensure that all hyperplastic glands are identified.