Comparative ultrastructural study of rat livers preserved in euro-collins or university of wisconsin solution

To find whether the liver can be procured after exclusive aortic perfusion, three organ perfusion models were used in three groups of donor rats. Group 1 underwent liver wash-out via the portal vein; in group 2, the kidneys alone were perfused via the aorta; and group 3 underwent simultancous aortic perfusion of liver and kidneys. All perfusion flow rates in the three groups were adjusted to physiological values. Harvested organs were transplanted and recipient animals were killed 4h after transplantation to study liver and kidney viability by using intracellular ATP measurement. Liver ATP was lower (P< 0.005) in the portal perfusion group (group 1: 1.396±0.412) than in the aortic perfusion group (group 3: 2.181±0.061). Kidney ATP was comparable in groups 2 and 3: 1.066±0.09 vs 1.059±0.273 (μmol/g) tissue. Liver cooling was quicker with portal perfusion than with the aortic flush (20°C in 20 s vs 15°C in 60 s). Aortic perfusion at a physiologic flow rate has no detrimental effect on renal viability studied by intracellular ATP measurement. We conclude that liver cooding via the aortic route only is a good alternative to portal perfusion and seems to give good preservation. Application of this observation to emergency procurement in humans is still the subject of controversy.

Study of kidney and liver viability in the rat after exclusive aortic perfusion using intracellular ATP measurement.

Portal circulation and the function of hepatocytes during isolated organ perfusion were compared between the rat liver perfused immediately after extirpation and the liver perfused after core cooling and six hours of preservation. Nine rat livers were extirpated after core cooling, preserved for six hours in University of Winsconsin (UW) solution at 4°C and then were connected to a perfusion chamber (hypothermic preservation group: 6-hr HP group). Six rat livers were immediately connected to the perfusion chamber after extirpation (control group). During 60 minutes of isolated liver perfusion, both portal circulation and the function of hepatocytes were determined every 10 minutes. Portal vein resistance increased and portal blood flow decreased during the first 20 minutes of perfusion and then stabilized in both groups. Portal vein resistance was significantly higher and portal blood flow was significantly lower for the first 10 minutes of perfusion in the 6-hr HP group, compared to the control group. The function of hepatocytes, determined by the rate of elimination of ammonia, oxygen consumption, and glucose availability were depressed in the 6-hr HP group, compared to the control groups during isolated liver perfusion. However, there was no statistically significant difference of portal perfusion and the function of hepatocytes between the two groups at the end of perfusion. The results of the present study indicate that the rat liver can be preserved in a satisfactory condition for six hours by the use of hypothermic preservation, coupled with core cooling.

Portal circulation and the function of hepatocytes during ex vivo perfusion of the rat liver preserved for six hours after core cooling.

Es erfolgten Lebertransplantationen am Schwein. Fur die Flushperfusion kamen kalte Ringerlosung (2°C)# warme Ringerlosung (15°C) und ein Blut-Ringer-Gemisch zur Anwendung. Mit Hilfe elektronenmikroskopischer Untersuchungen wurde die Bedeutung der sinusoidalen Schadigung demonstriert. Diese tritt bereits nach initialer Perfusion auf und nimmt nach Wiederdurchblutung des Organs zu. Hypoxie und rasches Abkuhlen erwiesen sich als wichtige pathophysiologische Faktoren bei der Schweineleberkonservierung.

I. Uerlings

Papers

On Pathophysiology of Preservation Damage in Liver Transplantation