BACKGROUND - After excision of an abnormal gland, the dynamics of intraoperative parathyroid hormone (PTH) levels signal whether or not more hypersecreting tissue is present. This quantitative assurance of operative success has led to targeted exploration of the hyperfunctioning gland(s). Some have questioned the need for intraoperative PTH monitoring (IPM) in the presence of positive nuclear scanning. The purpose of this study was to examine the accuracy of nuclear scans in correctly localizing and guiding the complete excision of all abnormal gland(s) in patients with sporadic primary hyperparathyroidism (SPHPT) and to demonstrate how IPM changed the operative management in these patients.
STUDY DESIGN - Five hundred nineteen consecutive patients with sporadic primary hyperparathyroidism had technetium 99-m-sestamibi scans (MIBI) as localization studies obtained before undergoing parathyroidectomy guided exclusively by IPM. All patients were either followed for more than 6 months, or their procedures were identified as operative failures. MIBI reports were correlated with operative findings, hormone dynamics, and postoperative outcomes.
RESULTS - Operative success was achieved in 506 of 519 patients (97%). MIBI correctly localized all involved glands in 411 patients (80%). Among the 105 patients (20%) with incorrect or negative scans, IPM changed the operative management in 86 of 105 (82%) by pointing out incomplete resection in patients with a single MIBI incorrect focus (21 of 28) or unrecognized multiglandular disease by scan (13 of 15); avoiding unnecessary exploration in patients with additional incorrect foci (20 of 21); and guiding the surgeon to successful excision or unilateral neck exploration in patients with negative MIBI (32 of 41).
CONCLUSIONS - MIBI as a single adjunct missed 87% of patients with multiglandular disease. Including patients with negative (8%) and incorrect (12%) MIBI, IPM changed the operative management in 17% of patients and led to operative success in 97%. We suggest that IPM should be used to guide parathyroid excision in every patient with sporadic primary hyperparathyroidism.