pigs have Has been dead for an hour. Cause: Cardiac arrest. But six hours after Yale researchers hooked up their bodies to a machine that pumps nutrient-rich fluids, their organs started showing signs of life again.
Although the organs didn’t suddenly start working normally, some of the cellular damage from reduced blood flow after death appeared to be reversed. The pig’s heart emits electrical activity. The cells in their kidneys, liver and lungs were functioning again and showed signs of repairing themselves.The discovery was published Wednesday in the journal nature, suggesting that cell death may be delayed longer than is currently possible. If these processes can be slowed down, that could mean more organs can be saved for transplant.
“This new system shows that not only can we slow cellular damage, but we can actually activate cellular repair processes at the genetic level,” said Brendan Parent, an assistant professor of bioethics at NYU who was not involved in the study.The study, but in nature beside. “It could force us to reconsider what we consider ‘dead.'”
In 2019, the Yale team challenged the idea that brain death is the end result, reporting that they had partially recovered pig brains within hours of being slaughtered. For the current experiment, the researchers wanted to see if the same approach could be used to restore other organs, in which blood substitutes were brought into the animal’s circulatory system.
“We restored some function of cells in multiple vital organs that would have died without our intervention,” Yale neuroscientist and author Nenad Sestein told reporters on a conference call Tuesday. These cells started functioning after undeserved hours, which tells us that even after an hour of death, cell death can be stopped and their function in multiple vital organs can be restored.”
With further refinement, the system could one day be used to expand the pool of human organs available for donation, said Dipali Kumar, president of the American Transplantation Society and a professor of medicine at the University of Toronto. “There is a severe shortage of organs for transplantation, and we certainly need new technologies that can help improve the supply of organs,” she said.
In the U.S., about 106,000 people are on the national transplant waiting list, and 17 people die every day while waiting for an organ transplant, according to the Federal Health Resources and Services Administration. Despite the huge demand, around 20% of organs are discarded each year due to poor quality. This can mean they’re too old or damaged, which can happen when organs are disconnected from their oxygen-rich blood supply for too long.
The standard practice for preserving transplanted organs is static refrigeration. Cooling an organ quickly after removal reduces its need for oxygen and prevents cell death, but it doesn’t save every organ. For patients who cannot be resuscitated, there is also growing interest in using a technique called extracorporeal membrane oxygenation (ECMO) to protect their organs for transplantation. ECMO machines are often used as life support for patients with severely damaged hearts or lungs, pumping blood out of the body to remove carbon dioxide and add oxygen before sending it back into the body.
