The utility of intraoperative PTH measurement in surgical parathyroidectomy after renal transplantation

Abstract

Intraoperative PTH (ioPTH) monitoring is used widely to guide surgery in primary hyperparathyroidism, but its reliability in renal transplant recipients is largely unknown. The aim of this study was to examine the utility of ioPTH monitoring in predicting long-term effectiveness of parathyroid tissue excision in renal transplant recipients, and to investigate the effect of parathyroidectomy on transplant function. Renal transplant recipients undergoing primary parathyroidectomy for persistent hyperparathyroidism were included. Intact PTH levels were measured at induction of anesthesia (PTH0), intra-operatively following removal of parathyroid tissue (PTH1) and 15 minutes after resection (PTH2). Serum PTH, calcium, phosphate and creatinine levels were measured up to 12 months postoperatively. 14 patients (9 male, mean age 55 ± 3 y) were included. PTH levels fell significantly from baseline (PTH0 237.4 ± 43.5 pg/ml) at both time points (PTH1 108.4 ± 38.3 pg/ml; PTH2 62.4 ± 31.3 pg/ml; p = 0.001). Three patients had a raised PTH level at 12 months post procedure. Analysis of these cases showed no difference in the fall of ioPTH, compared to patients in which the PTH level remained controlled. There was no significant change in renal function from baseline to 1 year post parathyroidectomy. Intra-operative and early postoperative measures of PTH may not be a reliable indicator of satisfactory parathyroid tissue excision in renal transplant recipients. Parathyroidectomy does not appear to be detrimental to long-term transplant function.