Normothermic Ex Vivo Liver Perfusion

Maintaining the liver at near-physiological temperature allows its cells to remain metabolically active during preservation rather than being placed in a largely inactive state. The circulating perfusate supplies oxygen and nutrients while removing metabolic waste, creating conditions in which organ performance can be observed. This makes preservation an active assessment period, not only a holding interval.

Routing oxygenated perfusate through both the hepatic artery and portal vein supports delivery through the liver’s two principal vascular inflows. This arrangement exposes the isolated organ to oxygen and nutrients through controlled circulation while allowing waste products to leave through the perfusion system. Using both routes is therefore central to maintaining the organ’s ex vivo metabolic activity.

Controlled pressure and flow create a defined circulation environment for the isolated liver and help clinicians observe its behavior under standardized conditions. These variables are managed alongside biochemical indicators rather than considered in isolation. Monitoring bile production and lactate clearance can then provide functional information that supports assessment of whether a donor graft remains viable for transplantation.

The approaches differ mainly in the preservation environment they provide. Normothermic ex vivo liver perfusion keeps the organ metabolically active with circulating oxygenated perfusate, whereas static cold storage does not provide that same active perfusion and monitoring framework. This distinction allows clinicians to evaluate graft function during preservation and may permit preservation beyond the period supported by static cold storage.

A workflow begins with an isolated donor liver placed on a perfusion system and connected so that perfusate can circulate through the hepatic artery and portal vein. The system maintains near-physiological temperature and regulates pressure and flow. During the run, clinicians monitor indicators such as bile production and lactate clearance to characterize graft function before transplantation.

Clinicians may consider this approach when a graft requires functional evaluation during preservation, particularly when the organ is considered higher risk. The system provides a controlled period in which biochemical and functional indicators can be monitored before transplantation. By supporting assessment and potentially extending preservation beyond static cold storage, it may help increase access to suitable livers.