Human lungs that are too damaged for transplantation can be “fixed” by connecting them to a live PIG
Damaged lungs from a deceased donor are often too damaged to be transplanted into someone who needs the life-saving organ.
But scientists have found a way to improve the condition of the lungs that are considered too battered to be of any use.
A large number of scientists from both Columbia and Vanderbilt University have channeled their inner Frankenstein and connected human lungs to an anesthetized pig.
Blood from the beating pig’s heart was fed into the lungs, which were powered by a ventilator, and then the blood was returned to the pig.
The experiment used five pairs of human lungs from donors classified as unsuitable for transplantation and each was coupled to a live pig for 24 hours.
The study found that after a day of ‘xenogeneous cross-circulation’, each individual set of lungs was in significantly better condition.
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Scientists have found a way to improve the condition of the lungs that are considered too battered to be of benefit to transplants. Damaged human lungs (left) were connected to a live pig and after 24 hours of cross-circulation, the organ’s condition improved dramatically (right)
Pictured, the experiment is ongoing. The human lungs can be seen in a protective cover and are connected to a ventilator and are connected to the blood circulation of an anesthetized pig, depicted under a sheet on the right side of the picture)
Respiratory diseases are the third leading cause of death worldwide and often the only permanent solution is a complete lung transplant.
Many die on the waiting list due to the lack of suitable donors and organs that have suffered serious but potentially reversible injuries.
Scientists have long searched for a way to increase the percentage of lungs making the cut and can be used in a transplant from the current level of one in five.
One method is called ex vivo lung perfusion (EVLP), a six to eight hour process that can restore marginal quality organs.
“Undoubtedly, EVLP has been a game changer for lung transplantation, but it remains limited in its ability to resuscitate severely injured lungs,” said Dr. Matthew Bacchetta, co-author of the study at Vanderbilt University.
But it is unable to take an important step in repairing severely damaged lungs that require much longer courses of treatment to become viable.
Researchers successfully took a few pig lungs last year and connected them to the bloodstream of an anesthetized pig.
They then discovered that lungs could be overhauled using the cross-circulation method and started investigating whether a pig host could do the same for human lungs.
Five sets of human lungs considered too poor for human transplantation were connected to a live pig. The pig’s heart and a ventilator allowed the lungs to function properly for 24 hours and to recover naturally. The method could be used to increase the amount of lungs available for transplantation
The academics say there are two ways to investigate how many lungs are available for transplantation. It would be seen that critically ill patients already awaiting transplantation for artificial lung support could serve as the cross-circulation host and play the role of the pig (pictured, a diagram of that potential scenario)
Five damaged lungs, each rejected for transplant, were donated to the study. One of the organs previously underwent EVLP but did not make the cut.
The pigs were treated with immunosuppressants to prevent lung rejection, and after 24 hours of plugging the damaged human lungs had improved.
Accurate analysis over the one-day procedure saw substantial improvements in tissue quality, inflammatory responses and respiratory function.
The researchers hope the method could be used to restore more human lungs from donors and increase the number of organs available for transplantation, potentially saving thousands of lives.
“We were able to repair a donor lung that did not recover on the clinical ex vivo lung perfusion system, which is the current standard of care,” said co-author Professor Gordana Vunjak-Novakovic.
“This has been the most rigorous validation of our cross-circulation platform to date, promising for its clinical utility.”
Dr. Bacchetta adds, “We knew this was our benchmark study, a human lung that did not pass advanced EVLP treatment.
“If we could get this to work on our system, we were on the right track. It was a eureka moment for our team. ‘
Scientists ‘revive’ some of the functions in a pig’s brain
Scientists have partially revived the brains of decapitated pigs that died four hours earlier in a groundbreaking study.
Experts used tubes that pumped a chemical mixture designed to mimic blood in the decapitated heads of 32 pigs to restore circulation and cellular activity.
Following Mary Shelley’s classic novel Frankenstein, billions of neurons started working normally and the death of other cells was reduced in six hours.
However, electrical brain activity in the brain associated with consciousness, perception and other high-level functions was not observed.
While the find is an exciting breakthrough, there is still no proof that anyone’s consciousness can be restored after they die, experts warn.
But it can open the door to saving mental powers in stroke patients, as well as new treatments that stimulate the repair of neurons after brain damage.
A research team led by the Yale School of Medicine extracted the pigs’ brains from slaughterhouses and placed them in a system they created called BrainEx.
The only lung that failed EVLP was refused for transplantation because of persistent swelling and fluid buildup that could not be resolved.
It was rejected for transplantation from multiple transplant centers across the U.S. and was eventually offered for research.
By the time the team received this lung, it had gone through two episodes of cold ischemia totaling 22.5 hours, plus five hours of clinical EVLP treatment.
After 24 hours of cross-circulation, the lung showed functional recovery, the researchers say.
Zachary Kon, director of the lung transplant program at NYU Langone Health, who was not involved in the study, noted, “As a lung transplant surgeon, I have seen that many patients do not receive lung transplants that they badly need.
“I find this work intriguing and hope that this technology will make more donor lungs available.”
The academics say there are two ways to investigate how many lungs are available for transplantation.
Either they can continue to use the existing method to connect human lungs to pigs and improve organs before they are sent for transplantation.
Or, critically ill patients already awaiting transplantation for artificial lung support could serve as the cross-circulation host and assume the role of the pig.
The person would then receive the lungs that he helped to regain full strength once he recovered.
“If we could improve the acceptance rate of 20 percent and increase it to 40 or 50 percent acceptance rate, we would essentially cut our waiting list and actually open the transplant to more people,” said Dr. Bacchetta.