Prospective evaluation of sestamibi scan, ultrasonography, and rapid PTH to predict the success of limited exploration for sporadic primary hyperparathyroidism

Background. The aim of this study was to determine the ability of localizing studies and rapid intraoperative parathyroid hormone (PTH) to predict the success of a limited approach in patients who then underwent bilateral exploration. Methods. Preoperative sestamibi-iodine subtraction scan and neck ultrasonography (US) were used to direct a focal (1-gland) and unilateral (1-sided) parathyroid exploration by using rapid intraoperative PTH determinations in 350 patients with sporadic primary hyperparathyroidism. Regardless of the findings, the contralateral side was then explored. Results. A single gland was predicted by sestamibi in 290 patients (83%), US in 298 patients (85%) and concordance of both in 205 patients (59%). Unilateral parathyroid exploration, directed by these studies, would correctly identify single gland disease in only 68%, 74%, and 79%, respectively. The addition of intraoperative PTH would increase the success rate to 73%, 77%, and 82%, respectively. The finding of 2 normal or 2 abnormal glands on 1 side would force bilateral exploration, and additional unsuspected pathology was found in 13%, 13%, and 9%, respectively. This failure rate would increase to 21%, 18%, and 15%, respectively, if The analysis assumed a focal rather than unilateral approach to the initial exploration. Conclusions. Even in patients with concordant sestamibi and US scans, and an appropriate PTH drop, additional abnormal parathyroid glands were found on complete exploration in 15%. A bilateral approach offers the best opportunity for the long-term cure of primary hyperparathyroidism.