3:30 PM Abstract No. 168 - Angiographic ablation for mediastinal parathyroid adenomas: experience at a tertiary referral center

Abstract

Purpose In expert hands, initial surgery for hyperparathyroidism was successful in more than 95% of cases; consequently pre-operative imaging was not routinely performed. Since the shift to minimally invasive parathyroidectomy imaging is routinely performed, usually Sestamibi scan and ultrasound. If those two tests are negative, in many institutions 4DCT is then considered. In those cases where the hyperparathyroid state persists following surgery, localizing and treating residual parathyroid tissue becomes much more challenging due to the increased incidence of ectopic location and post-operative scarring. When lesions are localized to or suspected to be within the mediastinum (even during the initial imaging in the preoperative patient), angiographic ablation provides an appealing, minimally invasive alternative to sternotomy or mediastinoscopy. The purpose of this study is to describe the pre-procedural work-up, technical approach and results of angiographic ablation of mediastinal parathyroid adenomas. Materials and Methods A retrospective review was performed of angiographic studies for localization and ablation of ectopic parathyroid adenomas. Pre-procedural imaging was reviewed as well as the electronic medical record for pre- and post-procedural laboratory values including calcium and PTH levels. Technical details of the angiographic procedure were recorded including the vessels accessed and the material used for ablation. Results 9 patients who underwent angiographic ablation of mediastinal parathyroid adenomas were identified. All patients had a suspicious lesion identified on angiography which was targeted for ablation. In all cases, there was an excellent angiographic response to ablation which was subsequently confirmed by normalization of the serum calcium levels. The internal mammary artery was the most frequently feeding vessel supplying these mediastinal lesions. Conclusion If a single feeding vessel supplying a parathyroid adenoma is identified it can be effectively treated by gradual injection of hyperosmolar contrast medium. Patients must be followed closely for development of symptoms, calcium and PTH levels. Angiographic ablation of mediastinal parathyroid adenomas is an infrequently performed procedure but can be an extremely effective minimally invasive technique to treat ectopic parathyroid adenomas. Familiarity with the pre-procedural work-up required and the technique is essential for achieving the optimal results.