To the Editor:
We read with great interest the article by Zhao et al[1] on the biliary tract injury caused by different relative warm ischemia time in liver transplantation in rats, in which they described a neoteric rat liver transplantation model–—"liver autotransplantation model". This procedure mixed the two steps of rat orthotopic liver transplantation i.e., the cold perfusion and implantation of donor liver. It was reasonable, feasible and absorbing, especially for the research purpose of ischemia-reperfusion injury in rat liver transplantation. But at the step of heparinization, the author did not clamp the hepatic artery (HA) before injection of heparin saline into the portal vein (PV). We think that it is inappropriate because arterial blood still flows into the liver at this time. That may lead to liver congestion and temporary decrease in circulating blood volume because of arterial blood stasis in the liver after the suprahepatic inferior vena cava is clamped, even though the abdominal aorta is blocked from the area above the celiac trunk to the area below the puncture point quickly. Microthrombosis is resulted from arterial congestion. Coagulated blood is one of the main mechanisms of biliary complications.[2] Subsequently, the result of this article would be interferred. Meanwhile, hypotension affects the survival of rats after operation. So we consider that the PV and HA should be clamped simultaneously at the step of heparinization.