Evaluation of the 'putative' role of intraoperative intact parathyroid hormone assay during parathyroidectomy for secondary hyperparathyroidism. A retrospective study on 35 consecutive patients: intraoperative iPTH assay during parathyroidectomy.

In the surgical treatment of secondary hyperparathyroidism (2HPT) of chronic kidney disease (CKD), a parathyroidectomy (PTx) of 4 glands can only be presumed as 'total', and indications for autoimplantation are complex. Intraoperative rapid parathyroid hormone assay could be useful to predict a radical resection. We evaluated iPTH levels 20 min and 24 h after a 4-gland PTx in 35 patients to determine the predictive value of intraoperative iPTH assay. We analysed retrospectively 35 patients affected by 2HPT of CKD, 13 undergoing total parathyroidectomy (TP) and 22 TP + autoimplantation (TPai), after removing 4 glands in 33 cases and 5 glands in 2. Intact PTH assays were acquired after 40 min before induction of anaesthesia, after removing both ipselateral glands, at 20 min after surgery and on postoperative day 1. 20 min after 4-gland PTx, a decrease of iPTH levels >80 % of the preoperative value was observed in 27 of 35 cases (77.1 %) and <80 % in 8 of 35 cases (22.8 %). In 6 of these 8 patients, iPTH levels were within the normal range 24 h after surgery. Although the intraoperative iPTH assays are of interest in the treatment of 2HPT, the predictive value of this method is not entirely satisfactory. In fact, a 4-gland PTx ensures euparathyroidism in most cases, even when intraoperative iPTH assays are not trustworthy; however, intraoperative iPTH assay, although not a perfect 'tool', is a proved aid for the surgeon in making his decision.