Effect of in situ hypothermic perfusion on intrahepatic pO2 and reactive oxygen species formation after partial hepatectomy under total hepatic vascular exclusion in pigs.

AIM: This study examined attenuation of ischemia and reperfusion (I/R) induced liver injury during liver resections by hypothermic perfusion of the liver under total hepatic vascular exclusion (THVE).
METHOD: Reactive oxygen species (ROS) formation, microcirculatory integrity and endothelial cell damage were investigated. Left hemihepatectomy (LHX) was performed without in situ perfusion (control-LHX, n = 5) or with concomitant in situ perfusion with hypothermic (4 degrees C) Ringer-glucose (cold-LHX, n = 5) or normothermic (38 degrees C) Ringer-glucose (warm-LHX, n = 5). Glutathione (GSH) and malondialdehyde (MDA) concentrations, tissue pO2 levels and hyaluronic acid (HA) uptake capacity were determined.
RESULTS: After cold, warm and control-LHX, 24 h survival was 5/5, 0/5 and 3/5, respectively. GSH levels were best preserved after cold-LHX during reperfusion. MDA levels increased in all groups without significant differences between the groups during reperfusion. Tissue pO2 levels increased after cold-LHX whereas after warm-LHX and control-LHX, pO2 levels decreased during reperfusion. HA uptake capacity remained normal after cold-LHX. After warm-LHX and control-LHX, HA uptake capacity decreased after 6 h of reperfusion but recovered after 24 h of reperfusion in the control-LHX group.
CONCLUSION: Moderate hypothermic perfusion protects the liver from I/R injury during LHX under THVE. This protective effect depended on maintenance of liver microcirculation rather than a reduction in ROS formation.