Hypothermic Machine Perfusion versus Cold Storage on the rescuing of livers from non-heart beating donor rats

CARNEVALE M.E.; BALABAN C.L.; GUIBERT E.E.; BOTTAI H.; RODRIGUEZ J.V.

Natal

Congreso; 7° Congresso Latino Americano de Órgâos Artificiais e Biomateriais; 2012

Sociedade Latino Americana de Biomateriais, Engenharia de Tecidos e Orgãos Artificiais

Hepatic transplantation has become the only safety solution to various irreversible liver problems. According to this, cold storage technique CS) was an important factor to achieve this success. Brain death donors are currently used in liver transplantation. However, a growing discrepancy between demand for organs and their availability from brain dead donors has led to a re-examination of non-heart beating donors (NHBD) to expand the pool of organs suitable for transplant. These organs may have a decreased survival after being transplanted because they suffered a period of warm ischemia. For the above reasons it is necessary to develop new strategies for the rescuing of these organs. There are experimental as well as clinical reports indicating that HMP (hypothermic machine perfusion, a dynamic technic where a continuous flow of preservation solution perfuse the organ) of marginal donor livers is superior to cold static preservation. However, there still are doubts as to which is the best perfusion preservation solution to use. For these reasons, we have developed a BES?Gluconate?Polyethylene Glycol based solution (BGP-HMP), a new solution for HMP of livers for transplants. The aim of this work was to compare the preservation efficiency of grafts excised from NHBD that have suffered 45 min of warm ischemia, employing CS and HMP methods. Material and methods: the portal vein and bile duct of Wistar rats were cannulated, the liver excised and connected on a recirculating perfusion system with 250 mL of BGP-HMP solution or flushed with 20 mL of cold Bretschneider solution (HTK) and then stored (0-4°C) in the same solution up to 24 h. HMP was performed up to 24 h at a constant pressure of 40 mmH2O (equivalent to 25% of the normothermic portal pressure) and a flow of 0.23 mL/min.gliver. The perfusion solution was air equilibrated during the HMP. After 24 h of HMP or CS, these livers were reperfused at 37C with Krebs-Henseleit Dextran solution (Balaban CL, Artif Organs 35:508-15, 2011). In both procedures, portal pressure and flow were measured and the intrahepatic resistance (IR) was calculated. Perfusate pH oscillations and enzymes (LDH, AST, and ALT) activities in perfusate were evaluated during normothermic reperfusion. Also, the O2 consumption of the liver, glucose and urea production and the bile flow were measured during the normothermic reperfusion period. Results: the portal flow (PF) and IR in both groups (n=5) showed statistical differences (p