Current and Potential Applications for Indocyanine Green in Liver Transplantation

Abstract

Indocyanine green (ICG) is a fluorescent dye taken up and almost exclusively cleared by the liver. Measurement of its clearance and visualization of its fluorescence make it suitable for a number of potential applications in liver transplantation including assessment of liver function and real-time assessment of arterial, venous, and biliary structures. ICG clearance can be used to assess donor graft quality before procurement and graft metabolic function before transplant using normothermic ex vivo machine perfusion. ICG clearance in the post–liver transplantation period is able to predict recipient outcomes with correlations to early allograft dysfunction and postoperative complications. After absorbing light in the near-infrared spectrum, ICG also emits fluorescence at 835 nm. This allows the assessment of vascular patency after reconstruction and patterns of liver perfusion in real time. ICG perfusion patterns after revascularization are also associated with posttransplant graft function and survival. ICG fluorescence cholangiography is routine in a number of centers and acts as an aid to identifying the optimal point of bile duct division during living donor liver transplantation to optimize safety for both donor and recipient. In summary, ICG is a versatile tool and has a number of useful applications in the liver transplantation journey including assessment of liver function, perfusion assessment, and cholangiography. Further research and clinical trials are required to validate and standardize its routine use in liver transplantation.

Rational Design of a Near-Infrared Ratiometric Probe with a Large Stokes Shift: Visualization of Polarity Abnormalities in Non-Alcoholic Fatty Liver Model Mice

“…It has been reported that indocyanine green mainly accumulated in the liver after intravenous injection. 58,59 As an ICG analog, we speculate that Cy-Mp has a similar biodistribution profile. To assess the ability of Cy-Mp to accumulate in the liver, C57BL/6 mice were injected with Cy-Mp (20 μM, 100 μL) via the tail vein.…”

Normothermic Machine Perfusion Systems: Where Do We Go From Here?

“…[68][69][70][71] Finally, nontoxic fluorescent dyes offer a means to visualize vasculature and organ function; for example, indocyanine green applied in liver NMP supports the real-time visualization of the intrahepatic biliary tree. 72 Using sensors in direct contact with the organ in question represents another attractive monitoring prospect; for example, implantable oxygen biosensors can monitor tissue oxygen tension, 73 whereas laser-Doppler technology can analyze organ microcirculation. 74…”

“…The administration of therapies through the perfusate has several benefits that make NMP an attractive therapeutic option, including more efficient delivery, lower doses, and reduced unwanted side effects in nontarget organs. 174 The immunomodulatory properties of mesenchymal stem cells 57–159 and multipotent adult progenitor cells 160–162 have shown beneficial effects during liver, lung, and kidney NMP, presumably due to their immunomodulatory properties, which prompt both anti-inflammatory and regenerative responses. 157,160–162 In human models, initially discarded kidneys 160 and livers 161 treated with multipotent adult progenitor cells or preterm-neonate progenitor cells 162 exhibited improved viability, even meeting established criteria.…”

Perfusion Programmes Start-Up and Viability Assessment: A Practical Guide to Ex-Situ Normothermic Machine Perfusion in Liver Transplantation

“…Surprisingly, the new generation of biomarkers based on advanced omics methods are still scarcely reported 49 . Other approaches, for example indocyanine green or methicillin clearance were proposed but not yet reported from clinical series [50][51][52] . Liver biopsy used to be the gold standard in liver transplantability assessment.…”