Establishment and evaluation of the system of extracorporeal liver perfusion in pigs

BACKGROUND; In recent years, extracorporeal liver per- fusion (ECLP) has been regarded as a treatment of acute liver failure ( ALF ); but the system of ECLP has many problems. The purpose of this experiment was to detect the factors affecting the system of ECLP and to establish a sta- ble and effective system of ECLP. METHODS; Livers were harvested from health pigs, ac- cording to the different styles of perfusion and oxygena- tion, which were randomly divided into 3 groups. The liv- ers in group A (n =4) were subjected to single portal vein perfusion, oxygenating perfusion blood; the livers in group B (n =4) to dual ( portal vein and hepatic artery) vessel perfusion, oxygenating blood, together; and the livers in group C ( n = 4) to dual (portal vein and hepatic artery) vessel perfusion, but oxygenating blood, separately. The perfusion time, the data of bile production, and hemody- namic parameters of extracorporeal livers in each group were tested. The histological examination of liver tissues from each group was performed at the end of perfusion. RESULTS: The perfusion time of the liver in group A is significantly shorter than in groups B and C (P<0.05). At 1 , 3 , 6 hours after perfusion, the data of bile production and hemodynamic parameters of livers in group A were sta- tistically different from those of livers in groups B and C (P<0.05). At 1, 3, 6 hours after perfusion, the data of group B were not statistically different from those of livers in group C (P>0.05). But at 12 hours after perfusion, the data of group B were statistically different from those of liv- ers in group C (P<0.01). CONCLUSION: The system of ECLP, which is performed by dual ( portal vein and hepatic artery) vessel perfusionand oxygenating blood separately, is more stable and effec- tive to keep the function of extracorporeal liver.

Preservation of non-heart-beating donor livers in extracorporeal liver perfusion and histidine-trytophan-ketoglutarate solution

AIM: To compare the preservation of non-heart- beating donor (NHBD) livers in cold histidine-trytophan- ketoglutarate (HTK) solution and extracorporeal liver perfusion (ECLP). METHODS: Livers harvested from health pigs were stored for 10 h in cold HTK solution (group A, n = 4) or perfused with oxygenated autologous blood at body temperature (group B, n = 4). Both groups were then tested on the circuit for 4 h. Bile production, hemodynamic parameters, hepatocyte markers and reperfusion injury of extracorporeal livers were tested in each group. Liver tissues from each group were examined at the end of reperfusion. RESULTS: At 1, 2, 3 and 4 h after reperfusion, bile production, hemodynamic parameters, hepatocyte markers and reperfusion injury of livers in group A were statistically different from those in group B (P < 0.05 or P < 0.01). CONCLUSION: ECLP is better than HTK solution to preserve NHBD livers. ECLP can assess the graft viabilitybefore liver transplantation.

Artificial and bioartificial liver support:A review of perfusion treatment for hepatic failure patients

Liver transplantation and blood purification therapy,including plasmapheresis,hemodiafiltration,and bioartificial liver support,are the available treatments for patients with severe hepatic failure.Bioartificial liver support,in which living liver tissue is used to support hepatic function,has been anticipated as an effective treatment for hepatic failure.The two mainstream systems developed for bioartificial liver support are extracorporeal whole liver perfusion(ECLP)and bioreactor systems.Comparing various types of bioartificial liver in view of function,safety,and operability,we concluded that the best efficacy can be provided by the ECLP system.Moreover,in our subsequent experiments comparing ECLP and apheresis therapy,ECLP offers more ammonia metabolism than HD and HF.In addition,ECLP can compensate amino acid imbalance and can secret bile.A controversial point with ECLP is the procedure is labor intensive,resulting in high costs.However,ECLP has the potential to reduce elevated serum ammonia levels of hepatic coma patients in a short duration.When these problems are solved,bioartificial liver support,especially ECLP,can be adopted as an option in ordinary clinical therapy to treat patients with hepatic failure.