Predicting the success of limited exploration for primary hyperparathyroidism using ultrasound, sestamibi, and intraoperative parathyroid hormone: analysis of 1158 cases.

OBJECTIVE: The aim of this study was to determine the success of limited neck exploration (LE) for primary hyperparathyroidism (1 degrees HPT).

METHODS: Between 1999 and 2007, 1407 patients with hyperparathyroidism underwent bilateral neck exploration (BE). Of these, 1158 patients with first-time sporadic 1 degrees HPT were analyzed prospectively. Based on surgeon-performed ultrasound (US) and sestamibi scan (MIBI), LE was initially performed. Regardless of results, BE followed to identify the presence of additional parathyroid pathology.

RESULTS: Of 1158 patients, 242 (21%) were found to require concomitant thyroid surgery thus excluding LE. Of the remaining 916 patients, a single abnormal gland was identified on MIBI in 682 (74%), US in 731 (80%), and concordance of both in 588 (64%). Unsuspected multiglandular disease (MGD) was identified at BE in 22%, 22%, and 20% of patients, respectively. Adding intraoperative parathyroid hormone sampling (IOPTH) further reduced the rate of unsuspected MGD to 16%, 17%, and 16%. Overall, IOPTH correctly predicted MGD in only 22%. Neither concomitant nonsurgical thyroid disease nor more stringent selection criteria (preop Ca>11 mg/dL and PTH>120 pg/dL) altered success rates. In patients with MGD, a subsequent gland identified was larger than the index gland in 23%. Ninety-eight percent of BE patients were cured of 1 degrees HPT.

CONCLUSIONS: This is the largest study to evaluate the prevalence of additional parathyroid pathology in patients who are candidates for LE. Limitations in localizing studies and IOPTH fail to identify MGD in at least 16% of patients, risking future recurrence.