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.