Diagnostic Accuracy of Intraoperative Intact Parathyroid Hormone Monitoring for Surgical Outcomes of Secondary Hyperparathyroidism.

BACKGROUND Intraoperative intact parathyroid hormone (IO-iPTH) monitoring has not reached a consensus in predicting surgical outcomes of secondary hyperparathyroidism. Here, we explore the predictive effect of IO-iPTH monitoring on surgical outcomes of secondary hyperparathyroidism as a potentially effective standard. MATERIAL AND METHODS We enrolled 119 patients who underwent total parathyroidectomy with autotransplantation from January 2016 to August 2019. Intact parathyroid hormone (iPTH) levels were tested 1 day before surgery (iPTHpre), 10 min after glands resection (iPTH10min), and 1 and 7 days after the operation (iPTHd1, iPTHd7). According to iPTHpre levels, patients were divided into a <2000 pg/ml group and a ≥2000 pg/ml group, and the cutoff values were compared. In patients with successful parathyroidectomy, the value of iPTHpre minus iPTH10min (iPTHdec) and relative-iPTH10min were compared between groups. RESULTS Using cutoff values, the predictive criterion was defined as iPTH10min ≤314.5 pg/ml or relative-iPTH10min ≤12.4%. In the iPTHpre ≥2000 pg/ml group, iPTH10min had a higher predictive value (318 pg/ml vs 218 pg/ml) whereas relative-iPTH10min had a lower predictive value (12.1% vs 20.3%). In patients with successful PTX, the iPTHdec value of the iPTHpre ≥2000 pg/ml group was significantly higher than that of the <2000 pg/ml group. Additionally, the relative-iPTH10min was significantly lower in the ≥2000 pg/ml group than in the <2000 pg/ml group. CONCLUSIONS An intraoperative predictive criterion of iPTH10min ≤314.5 pg/ml or relative-iPTH10min ≤12.4% is associated with effectively predicting surgical success of secondary hyperparathyroidism. The predictive value is affected by iPTHpre level; therefore, a variable prediction standard based on iPTHpre levels shall be established.