Background: Recurrent and/or persistent hyperparathyroidism (HPT) is an uncommon disease. Relatively few cases are seen by any one center or surgeon. Most of the prior reviews of this problem were done in the era prior to potentially accurate magnetic resonsance imaging (MRI) and sestimibi scan localization and do not reflect current preoperative localization technology.
Methods: All cases of recurrent or persistent parathyroidectomy seen in our institution between 1992 and 1996 were reviewed retrospectively to assess the predictive value of preoperative MRI, selective venous sampling, sestimibi scanning, ultrasound examination, and computerized tomography (CT) scanning. The preoperative localization studies were compared with the findings at operation, the pathology report, and the patient's long-term calcium status.
Results: Twenty-eight patients were operated upon at our institution for recurrent or persistent HPT during this time interval. The final pathology turned out to be: adenoma, 24; hyperplasia, 2; carcinoma, 2. The site at which the reoperative pathology was found was in the neck in 22 patients and intrathoracic requiring sternotomy in 6. The long-term outcome, i.e., serum calcium level at > 6 months postoperatively, was normocalcemia in 22 of 28 (85%), persistent hypocalcemia in 2 of 28, and persistent hypercalcemia in 2 of 28. Some combination of MRI, sestimibi, selective venous sampling, ultrasound, and CT scan was performed on all patients preoperatively. Preoperative MRI scans were performed on 26 of 28 patients. They correctly localized the side and site of the pathology in only 12, yielding a sensitivity of 66%. There were, however, no false positives; therefore, the positive predictive value of this test was 100%. Selective venous sampling was carried out on 26 of 28 patients and correctly localized in only 8 (sensitivity, 50%). Again, there were no false positives, yielding a positive predictive value of 100%. Sestimibi scanning was performed in 16 of 28, localizing in 8 (sensitivity, 50%). The positive predictive value of this test was 80%. Ultrasound was performed in 26 of 28 patients and localized in only 3, yielding a sensitivity of 17%, with a positive predictive value of 75%. Computerized tomographic scan was performed preoperatively only when all other investigations turned out to have been nonlocalizing and was therefore done in only four patients, one of whom had a positive CT scan showing an intrathoracic, intrapericardial adenoma.
Conclusions: These data demonstrate that despite the availability of what are putatively accurate preoperative localizing tests for previously unoperated cases, no one localizing test is particularly sensitive in reoperative parathyroid surgery. Magnetic resonance imaging and selective venous sampling, however, are complementary and when positive do accurately predict the site of the persistent/recurrent parathyroid pathology. Use of these preoperative localizing studies resulted in a successful outcome, i.e., normocalcemia or hypocalcemia in 93% of patients operated on.