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.

AngiotensinⅡor epinephrine hemodynamic and metabolic responses in the liver of L-NAME induced hypertension and spontaneous hypertensive rats

AIM To study hepatic vasoconstriction and glucose release induced by angiotensin(Ang)Ⅱ or Epi in rats with pharmacological hypertension and spontaneously hypertensive rat(SHR).METHODS Isolated liver perfusion was performed following portal vein and vena cava cannulation; AngⅡ or epinephrine(Epi) was injected in bolus and portal pressure monitored; glucose release was measured in perfusate aliquots. RESULTS The portal hypertensive response(PHR) and the glucose release induced by AngⅡ of L-NAME were similar to normal rats(WIS). On the other hand, the PHR inducedby Epi in L-NAME was higher whereas the glucose release was lower compared to WIS. Despite the similar glycogen content, glucose release induced by AngⅡ was lower in SHR compared to Wistar-Kyoto rats although both PHR and glucose release induced by Epi in were similar. CONCLUSION AngⅡ and Epi responses are altered in different ways in these hypertension models. Our results suggest that inhibition of NO production seems to be involved in the hepatic effects induced by Epi but not by AngⅡ; the diminished glucose release induced by AngⅡ in SHR is not related to glycogen content.

Implementing an innovated liver ex-situ machine perfusion technology:The 2018 Joint International Congress of ILTS,ELITA and LICAGE

The 2018 Joint International Congress of ILTS,ELITA and LICAGE were held in Lisbon,Portugal on May 23–26,2018.The exciting and innovative program brought together 1144 experts in liver transplantation(LT)such as surgeons,physicians or basic scientists from 61 countries.The presentations included 110 invited speakers,181 oral presentations,and 545 posters.This editorial highlights some of the most innovative and impactful presentations in

BRIEF HYPOXIA PRECEDING E.COLI BACTEREMIA DOWNREGULATES HEPATIC TNF-α PRODUCTION

Hepatic TNF production following gramnegative bacteremia or hypovolemic shock predisposes to acute lung injury. However, TNF expression may be modified by the manner in which the hepatic O2 supply is reduced and equally important, its timing relative to bacteremia. Brief secondary hypoxic stress of bufferperfused rat livers downregulates E. Coli (EC)induced TNF expression whereas lowflow ischemia preceding EC increases subsequent TNF production owing to reactive O2 species (ROS). Here we determined whether 30 min of constantflow hypoxia preceding 109 intraportal EC likewise increases antigenic and bioactive TNF protein concentrations during reoxygenation via production of ROS. Multiple groups (n=38) were studied over 180 minutes, circulation antigenic TNF decreased in H/R+EC vs. EC controls (1 939640 vs. 12 4072 476 g/L at t=180 min; P<001, along with TNF bioactivity). TNF protein were not restored to control levels in ALLO+H/R+EC. Thus, ECinduced hepatic TNF production and export is strongly O2dependent in intact liver regardless of the generation of ROS or the sequence of bacteremia and modest hypoxic stress.

Machine perfusion of the liver:Putting the puzzle pieces together

The realm of extended criteria liver transplantation created the'adjacent possible'for dynamic organ preservation.Machine perfusion of the liver greatly expanded donor organ preservation possibilities,reaching before unattainable goals,including the mitigation of ischemia-reperfusion injury,viability assessment,and organ reconditioning prior to transplantation.However,current scientific evidence lacks uniformity between studies,perfusion protocols,and acceptance criteria.Construction of collaborative research networks for sharing knowledge should,therefore,enable the development of high-level evidence and guidelines for machine perfusion utilization,including donor acceptance criteria.Finally,this approach shall guarantee conditions for further progress to occur.