Focused parathyroidectomy guided by intraoperative parathyroid hormone monitoring (IPM) may lead to higher failure rates because of missed multiglandular disease.
Retrospective review of prospectively collected data.
Tertiary referral center.
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.
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.
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.