Splenic artery ligation: A protection against hepatic ischemia/reperfusion injury in partially hepatectomized rats

Aim: In liver resection, the temporary occlusion of the hepatoduodenal ligament (Pringle maneuver) is often used. However, the maneuver causes ischemia/reperfusion (I/R) injury in the remnant liver. Heme oxygenase (HO)‐1 has a cytoprotective role against this injury. Our aim is to investigate whether splenic artery ligation induces HO‐1 expression in the liver and ameliorates the hepatic I/R injury in partially hepatectomized rats. Methods: Rats underwent splenic artery ligation by occluding the main splenic artery. Two days later, the total hepatic ischemia (Pringle maneuver) was conducted, and then a two‐thirds partial hepatectomy (PH) was performed just before the start of reperfusion. HO inhibitor was twice injected s.c. at 3 and 16 h before the Pringle maneuver. HO‐1 levels were determined by western blotting. Liver injury was biochemically assessed. Results: In normal rats, HO‐1 was highly expressed in the spleen, but not in the liver. Splenic artery ligation induced HO‐1 in the livers. When rats underwent 20 and 30 min of Pringle maneuver/PH, survival rates were 28% and 8%, respectively. Splenic artery ligation significantly improved both the survival rates: 73% and 56%, respectively. Under these conditions, administration of HO‐1 inhibitor at least partly negated the efficacy of splenic artery ligation. Splenic artery ligation also increased the recovery rate of the remnant liver mass and platelet counts in Pringle maneuver/PH‐treated rats. Conclusion: Splenic artery ligation was significantly effective on the hepatic I/R injury in partially hepatectomized rats. Induction of HO‐1 may be at least partly involved in the improvement of this injury.