Preserving hepatic artery flow during portal triad blood occlusion improves regeneration of the remnant liver in rats with obstructive jaundice following partial hepatectomy

In certain cases, major hepatectomy is essential and inevitable in patients with hilar cholangiocarcinoma and obstructive jaundice (OJ). The current study was designed to evaluate effects of a novel method of portal blood occlusion, where the portal vein was occluded (OPV) and the hepatic artery flow was preserved in rats with OJ that underwent partial hepatectomy. OJ was induced in rats by ligation of the common bile duct for 7 days. Subsequently, OJ rats underwent hepatectomy removing 76% of the liver following occlusion of the portal triad (OPT), OPV or without portal blood occlusion. Liver blood flow (LBF), liver damage and regeneration were assessed. The safety limit for the duration of liver ischemia was 20 min for OPT and 40 min for OPV in rats with OJ. OPT and OPV methods resulted in significantly decreased microvascular LBF in rats with OJ from 529.53 +/- 91.55 laser speckle perfusion units (LSPU) in the control to 136.89 +/- 32.32 and 183.99 +/- 49.25 LSPU, respectively. Liver damage was assessed analyzing levels of serum alanine transaminase and direct bilirubin, determining interleukin-1 and tumor necrosis factor- expression and histological examination. It was demonstrated that liver damage and caspase-3 and -9 expression in the liver were substantially reduced in the OPV group compared with the OPT group. In addition, the OPV method significantly improved liver regeneration in OJ rats, as indicated by increased rates of liver regeneration and expression of proliferating cell nuclear antigen and Ki-67 compared with the OPT group. Therefore, the OPV method may prolong the duration of portal blood occlusion, reduce liver injury and improve liver regeneration by preserving hepatic arterial flow during portal blood control in rats with OJ undergoing partial hepatectomy. The current study describes a novel technique, which may be applied in liver surgery in patients with complex jaundice.