Preserving Hepatic Artery Flow During Portal Triad Blood Inflow Occlusion Reduces Liver Ischemia-Reperfusion Injury in Rats

Background. Temporary portal triad clamping (Pringle maneuver) during liver resection can reduce intraoperative blood loss, but also correlates with liver ischemia and reperfusion (I/R) injury. The hepatic artery supplies 20%-30% blood but more than 50% O-2 to the liver. In this study, we explored if preservation of hepatic artery flow when performing portal triad blood inflow occlusion could reduce liver I/R injury while not increasing the blood loss. Materials and Methods. Three groups of rats were created: group SO (sham operation), group OPT (occlusion of portal triad under portal blood bypass), and group OPV(occlusion of portal vein under portal blood bypass). Blood flow was occluded for 90, 100, 110, and 120 min before reperfusion. Liver I/R injury was assessed by measuring the survival of rats within 7 d after operation, liver blood loss, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver tissue malondialdehyde (MDA), and Na+-K+-ATPase, and liver histology. Results. The 7-d survival of rats in group OPV was higher than in group OPT. The safe tolerance limit was 90 min for group OPT and 110 min for group OPV. Liver blood loss in group OPT and OPV were significantly less than in group SO. However, no significant difference was observed in the amount of blood loss between group OPT and group OPV. The group OPV had significantly lower ALT, AST, and MDA values on the first hour and first day post-reperfusion than in group OPT. The Na+-K+-ATPase activity in OPV group was significantly higher than in group OPT 1 h post-reperfusion. Hepatocyte injury was significantly less in group OPV than in group OPT on histopathology. Conclusions. These data indicate that continuously clamping the portal vein while preserving the hepatic artery did not increase blood loss significantly in a rat liver I/R model, however this maneuver induced less liver I/R injury. It is therefore suggested that preserving hepatic artery inflow during portal triad blood inflow occlusion might become an alternative maneuver in liver surgery due to its ability to extend the safe tolerant time limit in normothermic hepatic ischemia. (C) 2012 Elsevier Inc. All rights reserved.