With further research, the cutting-edge technique could one day help preserve human organs for longer, allowing more people to receive transplants.
The researchers used a system they developed called OrganEx that allows oxygen to recirculate through a dead pig’s body, preserving cells and some organs after cardiac arrest.
“These cells are working hours after they shouldn’t be working,” said Dr. Nenad Sestan, the Harvey and Kate Cushing Professor of Neuroscience and professor of comparative medicine, genetics and psychiatry at Yale, who led the study.
“And what this tells us is that the disappearance of cells can be stopped. And their functionality restored in multiple vital organs. Even an hour after death,” he said at a press conference.
The scientific journal Nature published the research on Wednesday.
“This is a truly remarkable and incredibly significant study. It shows that after death, cells in mammalian organs (including humans) such as the brain do not die for many hours. This is well into the postmortem period,” said Dr. Sam. Parnia, associate professor of critical care medicine and director of critical care and resuscitation research at the NYU Grossman School of Medicine, told the Science Media Center in London. Parnia was not involved in the investigation.
The OrganEx system pumps a fluid called perfusate, mixed with blood, through the blood vessels of dead pigs. The perfusate contains a synthetic form of the protein hemoglobin and several other compounds and molecules that help protect cells and prevent blood clots. Six hours after treatment with OrganEx, the team found that certain key cellular functions were active in many areas of the pigs’ bodies, including the heart, liver and kidneys, and that some functions of the organs
It builds on research published by the same team in 2019 that used a similar experimental system called BrainEx that delivered artificial blood to the brains of pigs, preventing the degradation of important neural functions.
How might the research be applied to humans?
Although the research is still very early and very experimental, the researchers said they hoped their work in pigs could ultimately be applied to humans, mainly in terms of developing ways to expand the window for transplants. The current supply of organs is extremely limited, with millions of people worldwide waiting for a transplant.
“I think the technology holds great promise for our ability to preserve organs after they are removed from a donor,” co-author Stephen Latham, director of Yale’s Interdisciplinary Center for Bioethics, said at the briefing.
“You could take the organ from a deceased donor and connect it to the perfusion technology, and maybe then be able to transport it over a long distance over a long period of time to get it to a recipient who needs it.”
The researchers made it clear that they were in no way bringing the pigs back to life and that more work would be needed to understand whether the organs were usable for transplants.
“We couldn’t say that this study showed that any of the organs in this pig were … ready for transplantation into another animal, we don’t know that they all work, what we’re looking at is the cellular and metabolic levels,” he said. explain Latham. “And we’re nowhere close to being able to say, ‘Oh my God, we’ve not only restored life to this pig, but to any of the individual organs.’ We can’t say that yet. It’s still too early.”
The research has the potential to lead to new treatment strategies for people who have a heart attack or stroke, Dr. Robert J. Porte of the University Medical Center Groningen in the Netherlands said in a article published together with the study.
“One could imagine that the OrganEx system (or its components) could be used to treat these people in an emergency. However, it should be noted that further research will first be needed to confirm the safety of the system’s components in specific clinical situations,” he said. Porte, who was not involved in the investigation.
However, Latham said that possibility was “quite remote”.
“This idea of ​​connecting (a) person who has had an ischemic injury, you know, someone who drowned or had a heart attack, I think is pretty far off. The potential short-term use much more promising here is with the preservation of organs for transplants. .”
The researchers used up to 100 pigs as part of the study, and the animals were under anesthesia when the heart attack was induced.
The research also helps scientists better understand the process of death, something that is relatively understudied, Sestan said.
“Within a few minutes after the heart stops beating, there’s a whole cascade of biochemical events triggered by a lack of blood flow, which is ischemia. And that means (a) that oxygen and nutrients that cells need to survive, they stop. And that starts to destroy cells,” Sestan added.
“What we showed … is that this progression to massive permanent cell failure, that doesn’t happen so quickly that it can’t be prevented or possibly corrected.”