Use of Indocyanine Green Fluorescence for Parathyroid Glands Preservation in Bilateral Axillo-Breast Approach Robotic Thyroidectomy

Joon Woo Chung¹, Joon-Hyop Lee¹, Hyeong Won Yu², Hyungju Kwon², Su-Jin Kim², Young Jun Chai³, June Young Choi¹, Seong Ho Yoo², Kyu Eun Lee². ¹Seoul National University Bundang Hospital, ²Seoul National University Hospital, ³Seoul National University Boramae Medical Center

Bilateral axillo-breast approach (BABA) robotic thyroidectomy has shown favorable cosmetic and surgical outcomes. With increasing use of BABA robotic thyroidectomy, many efforts have been made to reduce complications related to parathyroid glands and recurrent laryngeal nerves (RLNs). In this study, we focused on preservation of parathyroid by indocyanine green (ICG) fluorescence under near-infrared (NIR) light.

From 2013.12 to 2015.5, among patients who had underwent BABA robotic thyroidectomy due to thyroid cancers, 13 patients were enrolled with informed consents. The patients were given 10mg ICG intravenously after strap muscle dissection. By NIR integrated scope (illuminator: 805nm/filter: 825nm), ICG was excited and emitted fluorescence. Based on the time that fluorescence appeared and disappeared in thyroid and parathyroid, visualization durations with optimal identification time were estimated, with an attempt to find RLNs. Simultaneous intraoperative PTH assays were done for biochemical confirmation of parathyroid detected by ICG fluorescence. Patient demographics and clinico-pathologic characteristics were analyzed together.

The elapsed time to thyroid and parathyroid visualization were 211±120(s) and 218±94(s) with fluorescence duration of 17.6±2.6(min) and 20.8±6.0(min), respectively. In all cases we could distinguish parathyroid from thyroid. Though earlier enhancement of thyroid, parathyroid showed more focal and intense fluorescence pattern. RLNs didn't show ICG fluorescence in contrast to thyroid and parathyroid. PTH assay results suggested proper parathyroid identification had been done in all patients. In postoperative period mild transient hypoparathyroidism was reported in one patient, otherwise no recurrent RLN palsy occurred.

According to results of our study, parathyroid preservation using ICG fluorescence by NIR light is seemed to be feasible and safe in BABA robotic thyroidectomy. RLNs were also easily detected and saved by means of its non-fluorescent property. More randomized-controlled studies will be needed to support our conclusion and promote its application in practice.