Indocyanine green fluorescence angiography in parathyroidectomy for primary hyperparathyroidism

Introduction: Primary Hyperparathyroidism (PHPT) is a systemic pathology caused by an excessive secretion of parathyroid hormone. Parathyroidectomy is the treatment of choice in PHPT, and the success of surgery is based on precise localization of the abnormal parathyroid gland. Preoperative diagnosis makes use of imaging techniques and functional examinations, however these are insufficient in some cases for the precise location of the pathological gland. Therefore the need arises for an intraoperative localization technique. Materials and methods: We have retrospectively analyzed 20 consecutive patients with PHPT undergoing parathyroidectomy from April 2019 to September 2021, and divided them in two groups, in base of the use of Indocyanine Green (ICG) fluorescence during the surgery. Results: Of the twenty patients considered in the two groups, all received a preoperative ultrasound evaluation, while second level examinations were reserved for the more difficult cases, with small volume parathyroid adenomas. In the group where the fluorescence method was employed, fluorescence was especially useful in doubtful cases, allowing easier identification of the parathyroid adenoma and consequently a reduction of time and operatory risks. In two procedures using Indocyanine green, a fluorescence signal was weak. Conclusions: ICG represents a convenient and safe way to detect parathyroid adenomas. We found that ICG fluorescence was very useful in all patients with non-localizing preoperative imaging studies. However further investigation is needed, to demonstrate how ICGfluorescence could be a useful localization method during parathyroid surgery.