PTH secretion of "manipulated" parathyroid adenomas

Increased secretion of parathyroid hormone (PTH) and its fragments intraoperatively may influence PTH monitoring. The purpose of this study was to investigate whether "intended intraoperative manipulation" of parathyroid adenomas through mechanical stimulation (through squeezing or manual rubbing) would lead to increased PTH excretion. The different PTH fragments that result from this kind of manipulation were correlated and analyzed.

The enlarged glands of six consecutive patients who underwent open minimally invasive parathyroid exploration were "manipulated" for 30 s as soon as they had been identified. Blood samples were drawn before skin incision, at the beginning of the manipulation, 30 s, and at 2-, 5-, 10-, and 15-min intervals. Serum levels of (1-84)PTH were measured and (7-84)PTH was calculated.

An increased PTH secretion was documented in four of six "manipulated" single adenomas (mean PTH +/- SD 312 +/- 497 pg/ml). The PTH of one patient rose from 343 to 1,747 pg/ml. The ratio of (1-84)PTH to (7-84)PTH was 1.3 +/- 0.6 (median +/- SD):1 at "baseline" and 1.4 +/- 0.2:1 after manipulation. The coefficient of determination (R(2)) for the "baseline values" and for the values after manipulation is R(2) = 0.9816 and R(2) = 0.9985, respectively.

First, secretion of PTH varies widely after manual manipulation of adenomas. Second, PTH fragments circulate in the same ratio before and after "manipulation."