Machine Perfusion: How New Technology Keeps Organs Viable Longer

For decades, the standard method of organ preservation was brutally simple: pack the organ in ice and rush it to the recipient as fast as possible. The clock started ticking the moment the organ was removed — roughly 4 to 6 hours for a heart, 12 to 18 hours for a liver, and up to 36 hours for a kidney. If the organ couldn't reach a compatible recipient in time, it was lost. Machine perfusion is changing that equation entirely, and the implications for the transplant shortage are profound.

What Is Machine Perfusion?

Machine perfusion, also called ex-vivo perfusion, involves connecting a donated organ to a device that pumps a nutrient-rich, oxygenated solution through its blood vessels. Instead of sitting in a static, cold environment, the organ is maintained in a near-physiological state — warm or cold, depending on the technique — that preserves cellular function and allows continuous assessment of organ quality.

Types of Machine Perfusion

• Hypothermic machine perfusion (HMP): The organ is perfused at cold temperatures (4-10 degrees Celsius). This is the most established technique, widely used for kidneys, and has been shown to reduce delayed graft function compared to static cold storage
• Normothermic machine perfusion (NMP): The organ is perfused at body temperature (37 degrees Celsius) with oxygenated blood or blood substitute. This allows the organ to function during preservation, enabling real-time assessment of viability. NMP has shown particularly promising results for livers and lungs
• Subnormothermic perfusion: A middle ground between hypothermic and normothermic approaches, perfusing organs at 20-25 degrees Celsius. This technique is still under investigation but may offer advantages for certain organ types

How It Expands the Donor Pool

One of the most exciting applications of machine perfusion is its ability to reclaim organs that would previously have been discarded. Organs from older donors, donors with certain medical conditions, or donors after circulatory death (DCD) — as opposed to brain death — often sustain more damage during the donation process. With machine perfusion, transplant teams can assess these marginal organs in real time, determine whether they meet quality thresholds, and in some cases even repair damage before transplantation.

Studies published in the New England Journal of Medicine have demonstrated that livers preserved with normothermic machine perfusion had 50% less organ discard compared to those preserved with conventional cold storage. For a system in which roughly 20% of recovered organs are ultimately discarded, this represents a significant expansion of the usable donor pool.

Extending Preservation Time

Machine perfusion also extends the window of viability. While traditional cold storage imposes strict time limits, machine-perfused organs have been successfully preserved for 24 hours or more — and in some experimental cases, much longer. This additional time allows for better matching, longer-distance transport, and more careful surgical planning. It transforms the transplant process from a frantic race against the clock into a more deliberate, optimized procedure.

Current Adoption and Future Directions

Machine perfusion is already in clinical use at major transplant centers worldwide. The technology is approved for kidneys and livers in the United States and Europe, with lung perfusion systems also gaining regulatory approval. Research is ongoing for heart perfusion, with several promising devices in clinical trials. As the technology matures and costs decrease, broader adoption is expected.

Why This Matters

At YCOD, we follow these technological advances closely because they complement our policy work. Every organ saved by machine perfusion is a life saved — or a life that no longer needs to wait. Combined with opt-out legislation like Bill A07954, innovations in organ preservation can help us move toward a future where the transplant waiting list is a thing of the past. The science is advancing. Now policy needs to keep up.