In a groundbreaking long-term study spanning over a decade, researchers from a European consortium have demonstrated that deceased-donor kidneys preserved through cold machine perfusion consistently outperform those maintained by traditional static cold storage. Coordinated by the Department of Surgery at the University Medical Center Groningen (UMCG), this extensive follow-up furnishes compelling evidence that machine perfusion not only improves short-term transplant outcomes but also significantly enhances the longevity and function of transplanted kidneys even ten years post-implantation. The full findings were recently published in the prestigious New England Journal of Medicine, marking a major milestone in organ preservation and transplantation science.
Machine perfusion involves the continuous circulation of a hypothermic preservation solution through the kidney’s vasculature at temperatures between 1 and 10 degrees Celsius. This method contrasts sharply with static cold storage, where the organ is simply cooled and stored on ice without active perfusion. The dynamic nature of machine perfusion facilitates better oxygen delivery and removal of metabolic wastes, thereby maintaining organ viability and reducing ischemic damage. The machines used for this technique are generally compact and transportable, allowing for immediate application at donor hospitals and continuous use during transport to transplant centers.
The initial clinical trial that sparked this follow-up, known as the Machine Preservation Trial, previously established that machine perfusion yields superior early transplant outcomes compared to static cold storage. Early kidney function recovery was quicker in recipients of machine-perfused organs, and one- and three-year post-transplant survival rates for these kidneys were markedly higher. These trend-setting results were first shared with the medical community in landmark publications in 2009 and 2012, also appearing in the New England Journal of Medicine.
Recognizing that short-term clinical benefits can sometimes wane over time, the consortium embarked on a meticulous effort to monitor outcomes over a span of ten years. This involved contacting all 55 transplant centers across six European countries that had participated in the original trial involving 818 kidneys. The objective was to rigorously assess whether the initial advantages offered by cold machine perfusion would sustain or diminish after a decade.
The follow-up data conclusively showed that kidneys preserved by machine perfusion remained functional at a significantly higher rate compared to those stored statically—79 percent versus 73 percent, respectively. This gap became even more pronounced within kidneys sourced from ‘expanded-criteria donors,’ a classification comprising older or medically complex donors whose organs are typically less ideal. For these marginal kidneys, function retention on machine perfusion reached 70 percent, whereas static cold storage lagged at only 60 percent after ten years.
Notably, patient survival rates and measures of kidney function among those recipients whose organs were still working a decade after transplantation did not differ significantly between the two preservation methods. This suggests that while machine perfusion clearly enhances the durability and function of the organ itself, other factors influencing patient outcomes may be comparable. Still, the finding firmly supports the adoption of machine perfusion as the preferred method to optimize organ viability prior to transplantation.
Cold machine perfusion’s unique mechanism centers on hypothermic circulation. By gently flushing the kidney’s blood vessels with preservation fluid chilled between one and ten degrees Celsius, this technique minimizes cellular metabolism, reduces ischemia-reperfusion injury, and mitigates oxidative stress. Unlike static cold storage, where organs endure prolonged periods without active perfusion, harmful metabolic byproducts can accumulate, and cells may suffer damage that impacts long-term graft success.
The logistics of this technique are equally impressive, with most perfusion machines designed for portability and ease of use. They can be deployed immediately upon organ retrieval at donor hospitals, ensuring that kidneys receive continuous protection throughout transport. This continuous cooling and supply of preservation fluid interrupts detrimental ischemic processes that typically progress in organs stored on ice during static preservation.
Since the publication of the initial trial results, cold machine perfusion has rapidly become the preservation standard in many countries worldwide, revolutionizing organ transplant protocols. This wide-scale adoption has translated into improved kidney transplant outcomes for countless patients, aligning with clinical and ethical imperatives to maximize the utility and longevity of donated organs. Policy makers and healthcare organizations often require solid long-term data to justify coverage and reimbursement, making this new decade-long evidence crucial to support broader implementation.
The science community recognizes that any innovation must demonstrate sustainability beyond short-term benefits to transform clinical practice habitually. This study’s rigorous 10-year outcome data provide rare and invaluable assurance that cold machine perfusion’s advantages not only persist but become even more impactful with organs of marginal quality. This highlights the method’s potential to expand the usable donor organ pool by improving outcomes for kidneys that would otherwise be considered higher risk.
Looking ahead, the implications of these findings extend beyond kidney transplantation. They serve as a benchmark prompting exploration of machine perfusion’s potential application to other organs such as liver, heart, and lungs, where preservation remains a critical challenge. Further refining perfusion solutions, temperatures, and duration may unlock additional gains in organ viability and transplant success rates across multiple disciplines.
In summary, the decade-long follow-up from this multinational European study affirms cold machine perfusion as a superior preservation technique for deceased-donor kidneys compared to static cold storage. The marked improvement in long-term organ function, particularly among marginal quality organs, validates its routine clinical use and encourages the global expansion of this technology. This advance is a testament to how integrating engineering, clinical science, and collaborative research can tangibly enhance patient outcomes, extend graft life, and ultimately save more lives.
Subject of Research: Long-term outcomes of deceased-donor kidney preservation methods in transplantation
Article Title: (Details from provided content)
News Publication Date: November 6, 2025
Web References: http://dx.doi.org/10.1056/NEJMc2406608
References: New England Journal of Medicine publications from 2009, 2012, and 2025 regarding the Machine Preservation Trial and follow-up study
Image Credits: Not specified
Keywords: cold machine perfusion, kidney transplantation, organ preservation, static cold storage, hypothermic perfusion, transplant outcomes, deceased-donor kidneys, expanded criteria donors, long-term graft survival, ischemia-reperfusion injury, organ viability, transplant technology
Tags: benefits of cold machine perfusioncontinuous hypothermic perfusion methoddonor kidney preservation techniquesdynamic organ preservation methodsEuropean kidney transplant studyischemic damage reduction in organslong-term kidney transplant outcomesmachine perfusion in kidney transplantationNew England Journal of Medicine publicationorgan preservation advancementstransplant longevity and functionUniversity Medical Center Groningen research
