The exact etiology of nonanastomotic biliary strictures (NAS) with a patent hepatic artery after liver transplantation remains unclear so far. Microangiopathy is strongly suspected to be involved in the etiology, so sufficient flushing of peribiliary plexus (PBP) which directly nourishes the donor biliary tree may be pivotal to prevent NAS with a patent hepatic artery.~Solution of University of Wisconsin (UW solution) is a standard for liver graft flushing, but accused of high viscosity and hyperaggregation effect on erythrocytes by ingredient hydroxyethyl starch as well as initial vasoconstriction by high potassium content, which together constitutes a hindrance to solution penetration and thorough flushing of liver microcirculation including PBP. Several studies have revealed the relationship of high viscosity of UW solution with the development of NAS.~The investigators, therefore, have hypothesized that sequential perfusion with low-viscosity and high-viscosity preservation solutions might improve the patency of PBP in contrast with conventional sole perfusion with high-viscosity UW solution, and as a result, the incidence of NAS with a patent hepatic artery after liver transplantation would be significantly decreased.
The study was designed to investigate whether, compared with conventional sole perfusion with high-viscosity solution of University of Wisconsin (UW), sequential perfusion of liver grafts with low-viscosity and high-viscosity preservation solutions could further decrease the incidence of nonanastomotic biliary strictures (NAS) after liver transplantation.