Dosing of indocyanine green for intraoperative laser fluorescence angiography in kidney transplantation

Objective Sufficient blood supply is a crucial factor determining postoperative allograft function in kidney transplantation. Therefore, besides the surgeon's individual impression, a method for evaluating the quality of the organ's microperfusion is required. Laser fluorescence angiography with indocyanine green (ICG) is an emerging tool for this purpose. However, no reproducible quantification of ICG fluorescence has been performed in transplantation so far. Methods This retrospective two-center study was designed to evaluate the dosing of ICG for intraoperative laser fluorescence angiography in kidney transplantation. The Spy Elite® system (NOVADAQ, Canada) was employed for quantitative assessment of allograft microperfusion. ICG was administered systemically 5 minutes after reperfusion applying doses between 0.25 and 0.01 mg ICG per kg body weight. Quantitative assessment was performed with the implemented SPY-Q Software. Results A total of 57 kidney recipients were included in two centers. The generated curves showing ICG IN and EgR were not evaluable due to oversensing when doses exceeded 0.02 mg per kg body weight. Conclusions Fluorescence angiography with ICG is an emerging tool for the intraoperative quality control and evaluation of microperfusion in kidney transplantation. A dose of 0.02 mg ICG per kg body weight is recommended to ensure the quantitative assessment with SPY-Q.