Intraoperative Parathyroid Hormone Monitoring During Parathyroidectomy in Severe Secondary Hyperparathyroidism due to Kidney Failure.

BACKGROUND

The utility of intraoperative parathyroid hormone (IOPTH) monitoring during subtotal parathyroidectomy to predict long-term intact PTH levels in kidney failure remains uncertain.

METHODS

Diagnostic accuracy study in a cohort of 46 patients with severe, uncontrolled secondary hyperparathyroidism. IOPTH was measured before incision and at 10- and 30-min post-excision. Sensitivity, specificity, and AUC-ROC were assessed for predicting surgical success-defined as iPTH < 300 pg/mL (KDOQI criterion) over 6 months. We also assessed KDIGO criterion as secondary outcome (iPTH < 9× the upper limit of normal, defined as 792 pg/mL) All patients received postoperative calcium and active vitamin D.

RESULTS

Surgical success was achieved in 37 (80%) patients using the KDOQI criterion. Compared with the failure group, the KDOQI success group had lower median 10-min IOPTH (186 pg/mL vs. 495 pg/mL, p < 0.001) and 30-min IOPTH (112 pg/mL vs. 495 pg/mL, p < 0.001). The 10-min percentage decline in IOPTH was also greater in patients who experienced KDOQI success (91% vs. 85%, p = 0.008). AUCs for 10- and 30-min IOPTH in predicting KDOQI success were 0.86 (95% CI: 0.72-1.00) and 0.86 (95% CI: 0.73-1.00), respectively. AUCs for percentage decline at 10 and 30 min were 0.78 (95% CI: 0.63-0.92, p = 0.03) and 0.75 (95% CI: 0.60-0.92, p = 0.02), respectively. A 10-min IOPTH < 270.7 pg/mL yielded 89% sensitivity and 68% specificity for predicting KDOQI success. Using KDIGO criterion, 41 (89%) patients achieved surgical success, with similar trends observed.

CONCLUSIONS

In severe secondary hyperparathyroidism due to kidney failure, 10-min IOPTH is a strong predictor of surgical success, with < 270 pg/mL suggesting better outcomes; percentage decline and 30-min values add little benefit.