Extension of ischemic tolerance of porcine livers by cold preservation including postconditioning with gaseous oxygen

Background. Transplantation of organs from nonheartbeating donors was recom mended to reduce organ shortage, In vitro experiments with rat livers have shown that the warm ischemic tolerance of the liver may be extended by pers ufflation with gaseous oxygen during cold storage, The qualification of thi s method for procurement of livers harvested after cardiac arrest was teste d in an in vivo approach with pigs, Methods. Livers from 15 donor pigs were explanted, heparinized, flushed wit h and stored in University of Wisconsin solution for 4 hr at 4 degreesC, an d then implanted into 15 recipients. The organs were dissected immediately after cardiac arrest (group 1) or after 60 min of warm ischemia (groups 2 a nd 3), Group 2 livers received 75,000 IU of superoxide dismutase together w ith the flush solution and were persufflated with gaseous oxygen via the ve nous vascular system during cold storage. Main end point was survival after 5 days. Additionally, metabolic, functional and inflammatory criteria were measured in the blood. Results. All animals of the groups 1 and 2 survived, all animals of group 3 died within 3 hr after reperfusion, In all groups the blood parameters ref lected significant damage of the livers. However, the ischemic damage was c omparable in the groups 1 and 2 whereas the livers of group 3 exhibited sig nificantly higher levels of aspartate alanine aminotransferase and lactate dehydrogenase, and a significantly elongated partial thromboplastin time 1 hr after reperfusion (P=0.016), Conclusions. Venous systemic oxygen persufflation in combination with antio xidative medication is a promising new method of resuscitating ischemically altered livers from nonheartbeating donors for successful transplantation.