Protection of reduced-size liver for transplantation

The shortage of available organs for liver transplantation has motivated the development of new surgical techniques such as reduced-size liver transplantation. Ischemia-reperfusion (I/R) associated with liver transplantation impairs liver regeneration. Ischemic preconditioning is effective against I/R injury in clinical practice of liver tumour resections. The present study evaluated the effect of ischemic preconditioning on reduced-size liver for transplantation and attempted to identify the underlying protective mechanisms. Hepatic injury and regeneration (transaminases, proliferating cell nuclear antigen [PCNA] labeling index, and hepatocyte growth factor [HGF]) were assessed after reduced-size orthotopic liver transplantation (ROLT). Energy metabolism, oxidative stress, tumor necrosis factor-alpha (TNF) and interleukin-6 (IL-6) were examined as possible mechanisms involved in liver regeneration. Ischemic preconditioning reduced transaminase levels and increased HGF levels and the percentage of PCNA-positive hepatocytes after ROLT. This was associated with a decrease in oxidative stress following ROLT, whereas energy metabolism and hepatic IL-6 and TNF release were unchanged. The benefits of ischemic preconditioning on hepatic injury and liver regeneration could be mediated, at least partially by nitric oxide. These results suggest a new potential application of ischemic preconditioning in reduced-size liver transplantation.