Machine perfusion for 'marginal' liver grafts.

Due to the critical shortage of deceased donor grafts, clinicians are continually expanding the criteria for an acceptable liver donor to meet the waiting list demands. However, the reduced ischemic tolerance of those extended criteria grafts jeopardizes organ viability during cold storage. Machine perfusion has been developed to limit ischemic liver damage but despite its proven biochemical benefit, machine liver perfusion is not yet considered clinically due to its low practicability. In this review, we summarize our understanding of the role of machine perfusion in marginal liver preservation. The goal is to highlight advantages or disadvantages of current perfusion techniques and to explain the underlying mechanisms. We provide evidence for the need of a liver perfusion performance shortly before implantation, and point out promising designs.