Texture Analysis Using Indocyanine Green Fluorescence Measurement During Porcine Hypothermic Oxygenated Machine Perfusion.

BACKGROUND: Development of novel organ viability assessment methods during MP under hypothermic conditions is important to expand the donor pool with DCD donors for transplantation. This study proposed a novel quantitative method using Indocyanine Green (ICG) fluorescence image for assessing organ viability during hypothermic oxygenated machine perfusion (HOPE), specifically focusing on homogeneous flow distribution analyzed with the gray-scale level co-occurrence matrix (GLCM) method, which is one of the most effective texture analysis method. METHOD: The proposed method quantifies ICG image uniformity using GLCM's 'contrast' feature, defining an evaluation index h as the average contrast (𝑐𝑜𝑛𝑡𝑟𝑎𝑠𝑡𝑎𝑣𝑒) after 200 s of ICG inflow. Experiments involved porcine livers with 0 min (WIT0) or 45 min (WIT45) of warm ischemia, preserved by dual-hypothermic oxygenated machine perfusion (HOPE), then evaluated using autologous blood reperfusion under normothermic conditions with an Isolated Reperfusion Model (IRM). RESULTS: Qualitatively, WIT45 livers showed more heterogeneous perfusion with "localized non-fluorescent regions". Quantitatively, the evaluation index h indicated a strong positive correlation with portal vein resistance at 120 min during IRM (r = 0.70, p = 0.015). A correlation with hepatic artery (HA) resistance (r = 0.40) was also investigated. This method enables quantitative prediction of ischemic injury status before transplantation, which is crucial for making informed decisions about DCD and marginal organs. It could expand the possibilities for HOPE perfusion. CONCLUSION: In conclusion, the evaluation index h obtained from GLCM analysis of ICG fluorescence images in organs during MP can predict portal vein resistance induced by ischemic reperfusion injury before transplantation and is a method that can expand the possibilities of HOPE perfusion.