[Intraoperative serum parathyroid hormone measurement in the surgical treatment of hyperparathyroidism]

PTH(1-84) short half life permits us to monitor parathyroidectomy efficacy, confirming complete resection after unilateral surgical approach in some cases of primary hyperparathyroidism. Nevertheless, this utility has been tested in controlled clinical trials and there is no agreement regarding the extraction of samples, their processing and interpretation of results.

In 18 consecutive patients operated on for primary or secondary hyperparathyroidism, serum PTH(1-84) concentrations were assessed at different times before, during and after partial (in 11 patients with multiglandular illness) and total resections.

Initial PTH(1-84) concentrations very largely in different pre-resection samples, and these variations significantly affect post-resection percentage reduction. Plasmatic clearance of PTH(1-84) after incomplete resection follows a decreasing exponential curve towards new equilibrium concentrations. The difference is significant comparing with concentrations following complete resection only 5 minutes after, but the 95% intervals with a confidence level of 90% of confidence are exclusive only for determinations after 120 minutes.

The decrement of serum PTH(1-84) concentrations to 20% of the preresection levels 120 minutes after an adenomectomy confirms the complete removal of all pathologic parathyroid tissue. A less sharp decrement must be investigated and may justify an early surgical revision.