Intraoperative monitoring of PTH may be helpful to confirm total PTX for treatment of rHPT, but iPTH assays often fail to predict total PTX in patients with rHPT (7,15).
Between September 2000 and July 2002, 35 consecutive patients undergoing surgery for rHPT gave informed consent for participation in a prospective study protocol.
To monitor the success of the surgery, blood samples collected by the surgical team were assayed in a room adjacent to the operation theater equipped with a mobile laboratory, which we also used during surgeries for rHPT. In minimally invasive surgery for primary HPT, the criterion of a decrease in iPTH-R to <50% of baseline within 10 min after resection is helpful in differentiating between single-and multiple-gland disease (17).
A decrease in PTH(1-84) concentrations to <50% of baseline within 20 min after L-PTX has been reported to be predictive of cure in rHPT (8).
Insufficient PTX leading to persistent rHPT was observed only in 5 patients of group A, who had ~2- to 3-fold higher PTH plateau concentrations than group A patients who had sufficient PTX (P = 0.024-0.00002, two-tailed t-test).
The positive predictive values of intraoperative PTH monitoring to forecast persistence of rHPT because of insufficient PTX in these 24 patients reached 24% (5 of 21) with the iPTH assays and 100% (4 of 4) with the Bio-iPTH assay.
PTH monitoring during PTX can predict successful surgery in primary HPT (17), and may be helpful to confirm sufficient PTX in gland autotransplantation for rHPT. Autotransplantation does not influence PTH concentrations until several days after surgery, when PTH production in the transplanted tissue resumes (19); therefore, the PTH values in consecutive samples after total PTX reflect the PTH clearance rate.