Operative failure in the era of focused parathyroidectomy: a contemporary series of 845 patients.

HYPOTHESIS: Focused parathyroidectomy guided by intraoperative parathyroid hormone monitoring (IPM) may lead to higher failure rates because of missed multiglandular disease.

DESIGN: Retrospective review of prospectively collected data.

SETTING: Tertiary referral center.

PATIENTS: From September 8, 1993, through January 30, 2009, a total of 845 consecutive patients with sporadic primary hyperparathyroidism underwent focused parathyroidectomy guided by IPM at a single institution.

MAIN OUTCOME MEASURES: Parathyroid hormone dynamics and perioperative data were analyzed for factors affecting outcome. Operative failure was defined as hypercalcemia with elevated parathyroid hormone levels within 6 months after parathyroidectomy. Detailed intraoperative data from the failed operations were also reviewed.

RESULTS: Of 723 patients followed up for at least 6 months, 702 (97.1%) had successful parathyroidectomy, and 21 (2.9%) had failed parathyroidectomy. The major cause of operative failure was the surgeon's inability to find the abnormal parathyroid gland (16 of 21 patients [76.2%]). In the remaining patients, IPM results were false-positive in 5 of 21 patients (23.8%) or 0.7% overall. Among the cohort, IPM correctly identified missed multiglandular disease in 33 of 38 patients (86.8%). Patients having operative failure were more likely to have a history of thyroidectomy or parathyroidectomy and were less likely to have correct findings on technetium Tc 99m sestamibi or ultrasonographic localizing studies compared with patients having operative success.

CONCLUSION: Inability of the surgeon to find the abnormal parathyroid gland-not missed multiglandular disease-is the main cause of operative failure in focused parathyroidectomy guided by IPM.