Board of the 2nd Workshop on Artificial Organs, Biomaterials and Tissue Engineering

1.THE HYPOTHERMIC PERFUSION MACHINE(HMP).AP-PLICATIONS TO THE PRESERVATION AND/OR THE RES-CUE OF LIVERS FOR TRANSPLANT Rodriguez JV Centro Binacional(Arg.-Italia)de Investigaciones en Criobiología Clínica y Aplicada(CAIC),UNR.E-mail:jrodrig@fbioyf.unr.edu.ar The developing demand of donor organs is responsible for an in-creasing utilization of marginal donor organs(MDO)provided by people suffering from non-beating heart.These organs have a grow-ing vulnerability to ischemia-reperfusion injury and compromised repair mechanisms.Indeed,MDO have been associated with in-creased rates of delayed graft function and acute rejection rates.HMP offers the possibility of recovering these organs.Principles of HMP are based on controlled perfusion of the organ at low tem-perature,via the vascular bed which delivers oxygen and nutrients from the perfusate,while waste metabolites are continuously re-moved.But there are several points to be investigated respect to the methodology involved in the HMP to determine the appropriate practice to perfuse and recover MDO.These points are:1-perfu-sion route(portal vein alone,portal vein and hepatic artery,hepatic artery alone,retrograde perfusion via hepatic vein;2-perfusion pressure and flow(constant flow or constant pressure?,continuous or intermittent flow,pulsatile or not?,flow at 25 or 50%of the normothermic flow?;3-perfusate oxygenation or not?,how much oxygen may be delivered during HMP?;4-perfusion temperature,20,10 or 5°C?;5-perfusate composition:the choice of the appro-priate colloid and the Na+and K+concentrations.Is the addition of cytoprotectors,free-radical scavengers and iron chelators relevant during HMP?;5-could it be beneficial to utilize pharmacological maneuvers as the addition of bioactive gases(CO,NO,or H2S)during HMP?