A multidisciplinary team from Vanderbilt University Medical Center (VUMC) and Columbia University has shown that the lungs of injured human donors, and therefore discarded for transplantation, can be recovered.
The new technique, described in a study published last year in the scientific journal Nature Medicine, has the potential to increase the supply of lungs available for transplant, saving the lives of people who would otherwise die waiting for donors, waiting to move up the transplant list.
Lungs: difficult to use
The lungs are the least used organ for transplant: Only 20% of those obtained from donors are considered to be in acceptable condition. The author of the study says so Matthew Wand. Bacchetta is associate professor of Thoracic Surgery and Biomedical Engineering at VUMC.
If we could improve the acceptance rate by 20% to 40%, or even 50%, we would essentially eliminate our waiting lists and actually be able to allow more people to get transplants.
Matthew Wand, Vanderbilt University Medical Center
Cross circulation, lung recovered
Bacchus and his colleagues demonstrated in previous research that a cross-circulation technique applied to animals not only supported but rehabilitated the lungs of guinea pigs for four days. Current research also extends this success to human lungs considered too damaged for transplantation, keeping them for 24 hours.
Lung diseases are the third leading cause of death globally, and transplantation is the only definitive cure for patients in the terminal stages of the disease.
The current standard of care for donor lungs is ex vivo pulmonary perfusion (EVLP) , a mechanical support system that can preserve the lungs for up to eight hours but has limited means of rehabilitating them. The study showed that an unrecoverable lung for EVLP could be rehabilitated using the xenogeneic platform: connecting the organs to the bloodstream of a third guest (in this case pigs) recovers and regenerates them.
“Without a doubt, EVLP has been a game-changer for lung transplantation, but it remains limited in its ability to resuscitate severely injured lungs,” Bacchetta said.
The xenogenic platform for recovering lungs
The xenogeneic platform offers scientists two immediate research paths. First, it offers a new option for transplant solutions previously considered too damaged. Second, the xenogenic platform allows the lungs to be preserved to test further therapeutic interventions. And there's more: the cross-circulation platform can be used to recover other human organs and tissues, including livers, hearts, kidneys and limbs.
In short, cross circulation can eliminate the shortage of donors.
