Normothermic Machine Perfusion (NMP) for Kidneys or Livers

Beginning at around 35–37°C, Normothermic Machine Perfusion keeps kidneys and livers functioning during transplant preparation. Instead of slowing things down with ice, this method uses warm, oxygen-rich fluid - either blood or a substitute - to mimic natural conditions. While stored on the machine, the organ continues working much like it would inside a person. Because cells stay active, damage from lack of oxygen drops sharply. Function can be checked live, just before surgery begins.

During liver transplants, normothermic machine perfusion boosts use of lower-quality organs - especially those from donors after circulatory death or ones with fat buildup. Because the system mimics natural body conditions, medical teams observe how much bile forms, whether lactate drops, what happens to blood flow, and if enzymes behave normally prior to surgery. Less guesswork means fewer healthy-enough livers get thrown away. Preservation time stretches further under this method, helping hospitals schedule operations at safer moments instead of rushing overnight. One key shift: doctors now fix certain issues outside the body, removing excess fat or applying specific treatments while the liver stays alive on a machine.

Notably improved outcomes appear in kidney transplants using NMP, particularly when donor organs carry higher risks. While the organ is being perfused, medical teams monitor how much urine forms, along with blood movement through the kidney, oxygen use, and chemical balance inside tissues. Because these measurements reveal actual function, choices about whether to proceed with surgery gain clarity. Before placing the kidney into the body, bringing cellular energy stores back to normal seems to limit damage caused by sudden return of blood flow, boosting initial recovery speed.

Even so, NMP comes with increased expenses, demands specific machinery, also relies on skilled perfusion staff. Clear benchmarks for organ function remain under development. Yet the method shifts focus - away from mere storage toward dynamic evaluation and healing of organs - offering more donors while lifting success rates in transplantation.

Written by Aniket Kumar Sinha at Incisionary

References

Churchill, D. N., & Nicholson, M. L. (2018). Normothermic machine preservation of the liver: State of the art. Journal of Clinical Medicine, 7(11), Article 460. https://pmc.ncbi.nlm.nih.gov/articles/PMC5843699/

Zhang, X., Li, Y., Xu, Q., Wang, Y., & Yang, Y. (2023). Normothermic machine perfusion in liver transplantation — Bibliometric perspective of the top 100 most cited articles. Retrieved from https://www.researchgate.net/publication/390274862_Normothermic_machine_perfusion_in_liver_transplantation_a_bibliometric_analysis_of_the_top_100_most_cited_articles

Markmann, J. F., Abouljoud, M. S., Ghobrial, R., Bhati, C. S., Eghtesad, B., Klair, T., Neri, D., … OCS Liver PROTECT Trial Investigators. (2022). Impact of portable normothermic blood-based machine perfusion on outcomes of liver transplantation: The OCS Liver PROTECT randomized clinical trial. JAMA Surgery, 157(3), 189–198. https://pubmed.ncbi.nlm.nih.gov/34985503/

Jadlow, J. A., Pretto, E. A., Conte, M. S., & Kim, D. H. (2023). Portable normothermic machine perfusion improves outcomes in liver transplantation. JAMA Surgery. https://jamanetwork.com/journals/jamasurgery/fullarticle/2787486

Mergental, H., Perera, M. T. P. R., Laing, R. W., Muiesan, P., Isaac, J. R. E., Labuschagne, J., Stephenson, B. T., Cilliers, H., Mirza, D. F., & Friend, P. J. (2020). Transplantation of discarded livers following normothermic machine perfusion. Nature Communications, 11, Article 2939. https://www.nature.com/articles/s41467-020-16251-3

Moers, C., Smits, J. M., Maathuis, K. G., Treckmann, J., van Gelder, F., Napieralski, B. P., … Leuvenink, H. G. D. (2024). Outcomes of kidney perfusion techniques (including normothermic machine perfusion) for transplantation. Retrieved from https://pmc.ncbi.nlm.nih.gov/articles/PMC10298857/

Hosgood, S. A., Summers, D., & Nicholson, M. L. (2023). Normothermic ex vivo perfusion before transplantation of DCD kidneys. American Journal of Transplantation. https://pubmed.ncbi.nlm.nih.gov/39439024/