Indocyanine green fluorescence guided resection of parathyroid adenoma of the carotid sheath: a case report and review of the literature.

Background: Ectopic parathyroid tissue can pose difficulties in diagnosis, management, and resection of adenomas in patients with hyperparathyroidism. The use of multimodal pre-operative imaging is recommended due to the diverse anatomic presentation of parathyroid adenomas and the potential presence of multiple adenomas. Resection failure still can occur, however, indocyanine green (ICG) fluorescence imaging is an intraoperative tool that has potential to help address this challenge. In the case which follows we demonstrate the use of ICG fluorescence imaging to assist in successful resection of a parathyroid adenoma located within the carotid sheath. Case Description: We present the case of a 75-year-old woman with primary hyperparathyroidism due to a parathyroid adenoma localized to the left carotid sheath, posterior to the carotid artery. Careful resection was aided by ICG fluorescence guidance allowing for complete resection and immediate postoperative restoration of normal parathyroid hormone and calcium levels. The patient had no peri-operative complications and had an unremarkable post-operative course. Conclusions: The anatomical heterogeneity of parathyroid gland adenomas within and around the carotid sheath presents a unique diagnostic and surgical scenario; however, the use of intra-operative ICG, as presented in this case, has important implications for endocrine surgeons and surgical trainees alike. This tool provides improved intra-operative identification of the parathyroid tissue allowing for safe resection, especially in cases involving critical anatomical structures.