LIMITED ROLE FOR INTRAOPERATIVE INTACT PTH MEASUREMENT IN PARATHYROIDSURGERY

Primary hyperparathyroidism may be cured surgically by complete excisi on of abnormal parathyroid tissue. Reoperation for persistent hypercal caemia due to residual abnormal parathyroid tissue may be associated w ith a high complication rate. It is possible to assay intact parathorm one (iPTH) intraoperatively and as iPTH has a relatively short half-li fe, its measurement intraoperatively may be used to predict successful parathyroidectomy. We have studied intraoperative iPTH levels in a co nsecutive series of 33 patients undergoing surgery for primary hyperpa rathyroidism. We found that iPTH levels fell significantly (P < 0.05) from a median pre-excision level of 122 pg/ml to a median level of 36 pg/ml 20 min after excision. However, in 3/31 successful parathyroidec tomies, the intraoperative iPTH levels either remained unchanged or ha d risen. Reliance on intraoperative iPTH levels in these patients may have resulted in unnecessary re-exploration. We conclude that intraope rative iPTH measurement has limited usefulness as a predictor of succe ssful parathyroidectomy for primary hyperparathyroidism.