Optimizing the minimally invasive approach to mediastinal parathyroid adenomas

Background: Patients with refractory hyperparathyroidism after neck exploration may have a mediastinal parathyroid gland that has not been identified reliably with a single radiologic study. We report 17 patients who underwent minimally invasive resection for mediastinal parathyroid adenomas after confirmatory multipoint radiologic imaging. Methods: Fifteen patients underwent thoracoscopic procedures and 2 patients underwent mediastinoscopic procedures for resection of suspected mediastinal parathyroid adenoma. Preoperative localizing studies included sestamibi scan, computed tomography scan of the neck and chest, and selective venous sampling of parathyroid hormone levels. Once a mediastinal location was determined, thoracoscopic or mediastinoscopic resection was performed. Successful removal of parathyroid tissue was confirmed with a 50% or greater reduction in intraoperative parathyroid hormone levels. Results: Parathyroid adenoma was resected in 88% of patients after the operation. The cure rate was 100% in patients with two or more concordant studies locating parathyroid tissue in the mediastinum and 60% in those with one positive study. The thoracostomy tube was removed on median postoperative day 1 (range, 0 to 2 days). Median hospital stay was 3 days (range, 2 to 7 days). The most common complication was temporary hypocalcemia, which occurred in 18% of patients. Conclusions: Minimally invasive parathyroidectomy is an effective treatment of hyperparathyroidism caused by mediastinal parathyroid tissue. Targeted exploration depends on the guidance of preoperative localization studies and measurement of intraoperative parathyroid hormone levels to verify successful resection. Selective venous sampling and high-resolution computed tomography scanning can be helpful in patients with negative sestamibi scans.