With more research, modern technology may one day help preserve human organs for longer, allowing more people to receive transplants.
The researchers used a system they developed called OrganEx, which recirculates oxygen throughout the dead pig’s body, allowing cells and some organs to be saved after cardiac arrest.
“These cells are functional after a few hours,” said Dr. Nenad Sestan, Harvey and Kate Cushing Professor of Neurology and Professor of Comparative Medicine, Genetics and Psychiatry at Yale, led the study.
“This shows us that cells can be stopped from dying. And their function in several vital organs is restored. Even an hour after death,” he said at a news briefing.
“This is really amazing and incredibly important research. It shows that after death, cells in the organs of mammals, such as the brain (including humans), do not die for many hours. This is well into the postmortem period, “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 study.
The OrganEx system injects a fluid called perfusate mixed with blood into the blood vessels of dead pigs. Perfusate contains a synthetic form of hemoglobin protein 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 basic cellular functions were active in many areas of the pigs’ bodies, including the heart, liver, and kidneys, and that some organ function was restored.
How can research be applied to people?
Although the research is in its early stages and highly experimental, the researchers hope that what they did in pigs could eventually be applied to humans, primarily in terms of developing ways to expand the window for transplantation. The current supply of organs is extremely limited, and millions of people around the world are waiting for a transplant.
“I think the technology holds great promise for our ability to preserve organs after they are removed from the donor,” Stephen Latham, director of the Yale Center for Interdisciplinary Bioethics, said in a briefing.
“You can take an organ from a deceased donor, connect it to perfusion technology, and then maybe transport it over a long distance to get it to the recipient who needs it.”
The researchers have made it clear that they are by no means resurrecting the pigs and that more work needs to be done to understand the transplantability of the organs.
“We can’t say that this study shows that any organ in this pig is ready to be transplanted into another animal, we don’t know if they’re all working, what we’re looking at is … the cellular and metabolic level,” Latham explained. We can’t say, “Oh my god, we’ve restored not only this pig’s life, but also some organs.” We can’t say that yet, it’s too early.”
The research could lead to new treatment strategies for people who have had a heart attack or stroke, said Dr. Robert J., an employee of the Groningen University Medical Center in the Netherlands. Porte said in an article published in conjunction with the study.
“It is possible to imagine that the OrganEx system (or its components) can be used to treat such people in emergency situations. It is important to note that more studies are required to confirm the safety of the system components in specific clinical situations,” he said. Porte, who was not involved in the study.
However, Latham said such a possibility is “quite remote”.
“I think the idea of connecting with (a) person who has suffered an ischemic injury, you know, someone who’s drowned or had a heart attack, is pretty far-fetched.”
The researchers used up to 100 pigs as part of the study, and the animals were under anesthesia when the heart attack occurred.
The research will also help scientists better understand the process of death — something relatively understudied, Sestan said.
“Within a few minutes of cardiac arrest, there is a whole cascade of biochemical events caused by a lack of blood flow, which is ischemia. And the oxygen and nutrients that cells need to survive stop. And that starts to destroy cells,” Sestan added.
“What we showed… It is a progression to massive permanent cell damage that is so rapid that it cannot be prevented or repaired.”