Increasing the Donor Pool with Normothermic Liver Perfusion
Normothermic liver perfusion has become one of the strongest levers transplant programs have for expanding usable donor livers. The technique maintains physiological conditions during preservation, enables real-time viability assessment, and supports safe transplantation of grafts that static cold storage alone would leave unusable. Programs that adopt normothermic machine organ perfusion consistently expand their acceptance criteria without compromising outcomes.
You already know the pressure of long waiting lists and the frustration of watching viable-looking livers get declined for lack of assessment tools. Normothermic perfusion turns that assessment gap into a data-driven acceptance decision your team can defend clinically. The strategies below explain how programs use the technique to grow their donor pool safely.
How Does Normothermic Liver Perfusion Increase the Donor Pool?
Normothermic liver perfusion increases the donor pool by maintaining livers at near physiological temperature (35 to 38 degrees Celsius), enabling real-time viability testing, and safely extending preservation windows so programs can accept extended-criteria and donation after circulatory death (DCD) livers previously declined under static cold storage. You gain functional data on hepatic artery flow, portal vein flow, lactate clearance, and bile production before transplant. The result is more usable livers and better outcomes on the marginal grafts programs choose to accept.
Why Static Cold Storage Limits Donor Pool Expansion for Liver Programs
Static cold storage served liver transplantation well for four decades, but its limitations become the bottleneck when programs try to expand the donor pool. However, wet ice-based preservation offers no viability data during storage, which forces acceptance decisions on donor history alone. Consequently, programs default to declining extended-criteria and DCD livers to avoid the risk of primary non-function.
The Q10 effect slows metabolism during cold storage but does not stop it, and metabolic waste continues to accumulate across the preservation window. Meanwhile, marginal livers with steatosis, prolonged warm ischemia, or older donor age carry higher baseline risk that static preservation cannot mitigate. Every declined marginal liver reflects an assessment gap, not a definitive quality judgment.
The utilization impact is substantial, with Organ Procurement and Transplantation Network (OPTN) data showing that roughly 22 percent of procured livers are discarded before transplantation, and many more are never offered at all. As a result, waiting list mortality stays high even as marginal grafts sit unused.
Ultimately, the assessment gap is what caps donor pool expansion for programs relying on static cold storage alone. Machine preservation is now the operational path to broader modern organ preservation flexibility across liver programs.
How Normothermic Liver Perfusion Turns Viability Assessment Into Acceptance Decisions
Normothermic liver perfusion maintains the graft at physiological temperature (35 to 38 degrees Celsius) with oxygenated blood-based perfusate, supplements, and controlled pressure. Consequently, the liver functions ex situ during preservation and generates measurable viability data your team can act on. Assessment becomes an active clinical process rather than a hopeful assumption.
A systematic review in HPB Surgery documented Mergental criteria requiring perfusate lactate under 2.5 mmol/L, bile production within 2 hours, pH above 7.3, hepatic artery flow above 150 mL/min, and portal vein flow above 500 mL/min. Livers meeting these criteria demonstrate viability regardless of their static-preservation risk profile.
Furthermore, the same review reported that the Nasralla RCT found 93 percent less likelihood of early allograft dysfunction in DCD livers preserved with NMP compared to SCS. Discard rates in that trial were 11.7 percent for NMP versus 24.1 percent for SCS.
The viability data also gives receiving surgeons a defensible basis for accepting livers that would otherwise be declined. Similarly, programs adopting NMP consistently expand acceptance criteria while maintaining outcomes across high-risk liver recovery cases.
Categories of Marginal Livers That Become Usable With Machine Preservation
Machine preservation makes several categories of marginal livers clinically usable that static cold storage would leave on the table. Every category represents a specific expansion of your program's donor pool. In practice, the categories below are drawn from current NMP literature and clinical adoption patterns.
• DCD Livers With Longer Warm Ischemia: NMP mitigates warm ischemic injury and gives surgeons real-time viability data before implantation.
• Steatotic Livers: Machine preservation supports assessment of macrosteatosis impact through active perfusion parameters rather than static biopsy alone.
• Older Donor Livers: Viability parameters during NMP help programs accept older grafts with defensible clinical data.
• Livers Requiring Extended Preservation: NMP safely extends preservation windows, letting programs accept livers requiring longer transport or overnight scheduling.
• High-MELD Recipient Cases: Real-time viability confirmation supports transplantation into higher-acuity recipients where PNF risk carries greater consequence.
Meanwhile, comparative NMP outcomes reviewed in European Journal of Transplantation documented ITBL rates of 0 to 10 percent and utilization rates spanning 12 to 85 percent across international programs. Programs investing in machine preservation build high-risk transplant recovery capacity that would otherwise sit unused.
How Specialist Support for Normothermic Liver Perfusion Expands Program Capacity
Notably, Gold Standard Preservation operates a dedicated liver NMP service line, and the direct benefit is a specialist team ready for the technical and operational demands of every NMP case your program accepts.
Support runs from initial NMP circuit setup through real-time viability parameter monitoring and receiving handoff. Specialists track lactate, pH, hepatic artery flow, portal vein flow, and bile production against Mergental criteria throughout the preservation window. Consequently, your surgical team receives a complete viability profile before making the acceptance decision.
Furthermore, GSP supports liver programs across current and emerging NMP platforms without vendor lock-in. Standardized workflows across high-risk liver recovery cases help programs expand acceptance criteria without expanding operational risk. Longer preservation windows also give your team scheduling flexibility for daylight-hour transplants.
The result is a liver NMP workflow where clinical execution, data capture, and acceptance decisions run on one continuous thread. Programs supported this way build a sustainable perfusion program that grows donor pool capacity case after case.
Ready to Expand Your Liver Program's Donor Pool?
Normothermic liver perfusion has become the operational path to donor pool expansion for programs serious about reducing waiting list mortality. Peer-reviewed data supports the safe transplantation of extended-criteria and DCD livers previously declined under static cold storage. The technique gives your team viability data, defensible acceptance criteria, and outcomes that hold up in the recipient OR.
Gold Standard Preservation partners with transplant centers and organ procurement organizations nationwide to deliver device-agnostic clinical support, real-time viability monitoring, and 24/7 operational readiness across liver recovery and machine organ perfusion. Book a conversation with our team about the specialist support your liver program's next expansion deserves.