Cold-to-warm machine perfusion of the liver: a novel circuit for an uninterrupted combined perfusion protocol

International audienceBackground: Ex-vivo perfusion of liver grafts is associated with promising results for the preservation of marginal grafts. Recent studies highlight the need for a combination of perfusion conditions, such as hypothermic followed by normothermic perfusion. While comprehensive machines dedicated to liver perfusion have been developed, these systems remain costly and poorly adaptable to perfusion condition switch, which requires a complete interruption of the perfusion process. Our team aimed at developing an adaptable and simple circuit for uninterrupted ex-vivo liver perfusion.Methods: Together with specialized bioengineers, we developed a highly adaptable circuit that can fit on already pre-existing extracorporeal oxygenation machines routinely used in cardiovascular surgery. This circuit, owing to its reservoir, allows any type of perfusion conditions without interrupting the perfusion process.Results: In a preliminary study, to assess the technical feasibility of liver perfusion using our circuit under different conditions, we performed 7 perfusions of discarded liver grafts. HOPE and DHOPE hypothermic perfusion could be performed, and a switch to normothermia was easily possible within seconds. From there, a dynamic perfusion sequence model was developed.Conclusion: This circuit may represent a simpler alternative or a new refinement to existing perfusion systems allowing uninterrupted combined perfusion protocols