Hypothermic reconditioning in organ transplantation

To summarize the recent understanding of postpreservation reconditioning of organ grafts.

Notable parts of ischemia-associated tissue alterations during static storage do not represent irreversible tissue damage, but rather biochemical and molecular disturbances of cellular homeostasis. Manifestation of irreversible organ injury upon warm reperfusion, triggered by these ischemic cellular disorders, could in large part be circumvented by a brief period (1-2 h) of hypothermic oxygenation between cold storage and transplantation. The procedure called 'hypothermic reconditioning' has first been found to be effective in the liver using simple gaseous oxygen persufflation, but was seen equally effective using hypothermic machine perfusion. Under certain circumstances, anoxic, but pulsatile vascular perfusion may suffice to alleviate ischemia-induced proinflammatory phenotype on vascular endothelium.

Vascular and parenchymal tissue homeostasis can be restored to a notable extent in cold-preserved organ grafts by hypothermic reconditioning: a short period of preimplantation treatment allows for better graft function after transplantation in livers and kidneys. Hypothermic reconditioning represents a promising and easily applicable tool for post hoc enhancement of organ viability in marginal grafts and should be validated in randomized controlled trials.