BACKGROUND - Limited parathyroidectomy guided by intraoperative parathyroid hormone (PTH) assay (QPTH) is highly successful (97% to 99%) in predicting postoperative eucalcemia, usually with less extensive dissection when compared with bilateral neck exploration. Because fewer glands are excised when resection is guided by QPTH as opposed to resection guided by gland size, a higher recurrence rate may occur. Recurrence rate after bilateral neck exploration is 0.4% to 5%, but frequency of recurrence after limited parathyroidectomy is unknown. This study reports outcomes of this operative approach in sporadic primary hyperparathyroidism.
STUDY DESIGN - Four-hundred twenty-three patients with sporadic primary hyperparathyroidism undergoing limited parathyroidectomy, followed 6 months or more or considered operative failures, were studied. In most patients, calcium and PTH levels were measured immediately after operation, and then at 2 and 6 months and yearly intervals. Operative failure is defined as hypercalcemia and high PTH within 6 months after operation, and recurrent hyperparathyroidism is hypercalcemia and elevated PTH occurring after a successful parathyroidectomy. Recurrence distributions were estimated using Kaplan-Meier analysis.
RESULTS - The success rate of limited parathyroidectomy is 97% (412/423). Four-hundred six patients were eucalcemic over an average of 34 months (median 27, range 6 to 118 months) of followup and recurrent hyperparathyroidism developed in 6 of 412 (1.5%). Estimated 5 years recurrence-free rate was 97% (95% confidence interval, 91% to 99%). Earliest and latest recurrences were diagnosed at 24 and 83 months, respectively. QPTH results did not predict any recurrence. Overall success rate was achieved, with multiple gland resections performed in only 3% of patients.
CONCLUSIONS - Recurrence rate after limited parathyroidectomy is similar to rates reported after bilateral neck exploration. Parathyroidectomy guided by QPTH is successful not only in resolving hypercalcemia in the short term, but also in providing longterm eucalcemia.