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Updated: Jun 4, 2025
Ex Situ Normothermic Machine Perfusion of Donor Livers
Published on: May 26, 2015
Perfusion Pressures and Weight Loss During Normothermic Machine Perfusion of Human Donor Livers
Bianca Lascaris1, Silke B Bodewes1, Adam M Thorne1
1Department of Surgery, Section of Hepatobiliary Surgery and Liver Transplantation, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Background:
Normothermic machine perfusion (NMP) is increasingly used to preserve and assess donor livers prior to transplantation. Due to its success, it is expected that more centers will start using this technology. However, NMP may also cause adverse effects.
Methods:
In this retrospective, observational study, we investigated the effect of NMP pressures on donor liver weight, post-transplant outcomes, and hepatic perfusion characteristics. A total of 36 livers were transplanted after NMP. NMP perfusion pressure settings were lowered from a median (IQR) of 47 mmHg (42-54) to 34 mmHg (30-39) for the hepatic artery (HA), and from 8 mmHg (7-10) to 7 mmHg (6-8) for the portal vein (PV) to diminish potential edema formation inside the liver.
Results:
This change appeared to lead to a reduction of liver weight after NMP (-22 g to -143 g, p = 0.02), without affecting the PV flow velocity (35.5 to 48.0 cm/s, p = 0.54), or hepatocellular injury markers during NMP (AST 1511-1148 U/L, p = 0.44; ALT 318-849 U/L, p = 0.35), and post-transplantation outcomes. Changes in liver weight correlated significantly with the applied PV pressure during NMP (r = 0.52, p < 0.01) and the HA flow (r = 0.38, p < 0.05).
Conclusion:
NMP can lead to a reduction in liver weight, which might be masked by edema when high perfusion pressures are used. We encourage applying the lowest perfusion pressures possible to reach adequate flows and oxygen supply during liver NMP.
