After inserting a solution called OrganEx into the veins of pigs that had been dead for an hour, scientists were able to revive the cells in the pigs' organs, according to a study published in Nature. This offers a potential tool to increase the number of available organs for transplants and raises questions about the definition of death.

Details on the study

The study built upon a previous study conducted by researchers from Yale University in which a device called BrainEx pumped synthetic blood into 32 brains that came from pigs who had been dead for hours. The researchers observed several signs of the brains regaining function after being connected to BrainEx and receiving the solution.

For the new study, the Yale researchers inserted the OrganEx solution—which contains nutrients, anti-inflammatory medicine, drugs preventing cell death, nerve blockers, and artificial hemoglobin mixed with the blood of each animal—into the veins of pigs that had been anesthetized and killed an hour before.

The researchers found the hearts in the pigs who received OrganEx started beating, and the cells in a number of organs—including their hearts, livers, kidneys, and brains—started functioning again. They also found the pigs didn't get stiff, as a typical dead pig would.

By comparison, other pigs that had also been dead for an hour and were treated with extracorporeal membrane oxygenation (ECMO)—a machine that's used to pump blood out of the body, oxygenate it, then return it back to the body—became stiff, their organs swelled and were damaged, and their blood vessels collapsed.

The potential for organ transplants, treatments

The authors of the study said they were shocked at OrganEx's ability to revive cells in the dead pig organs.

"We did not know what to expect," said David Andrijevic, a neuroscientist at Yale and an author of the study. "Everything we restored was incredible to us."

The authors said one goal of OrganEx is to ultimately use it to increase the supply of human organs available for transplant.

According to Robert Porte, a transplant surgeon at the University of Groningen in the Netherlands, most countries have a five-minute "no touch" policy after a patient's respirator is turned off before transplant surgeons come to remove organs. However, "before you rush to the OR, additional minutes will pass by," and sometimes organs can end up damaged to the point they're unusable, he said.

Because of that, between 50% and 60% of patients who die after life support ends and whose families want their organs donated are unable to be donors, the New York Times reports.

If OrganEx is able to revive those organs, the effect "would be huge," Porte said, significantly increasing the number of organs available for transplant.

"You could take the organ from a deceased donor, and hook it up to the perfusion technology, and perhaps then be able to transport it long distance over a long period of time to get it to a recipient who needs it," said Stephen Latham, director of the Yale Interdisciplinary Center for Bioethics and co-author on the study.

Alexandra Glazier, president of New England Donor Services, said the OrganEx system, could be "a game-changer in addressing the organ shortage."

However, Latham cautioned that this research is in the very early stages.

"We couldn't say that this study showed that any of the organs of this pig were … ready for transplant into another animals, we don't know that they're all functioning, what we're looking at is at the cellular and metabolic levels," he said. "And we're nowhere near being able to say, 'Oh, my goodness, we've restored life not only to this pig, but to any of the individual organs.' We can't say that yet. It's still very much too early."

Porte added that OrganEx could also be used to treat heart attack and stroke patients. "One could imagine that the OrganEx system (or components thereof) might be used to treat such people in an emergency," he said. "Of note, though, more research will first be needed to confirm the safety of the system's components in specific clinical situations."

Latham cautioned however that application of OrganEx is also "quite far away."

"This idea of hooking up [a] person who had suffered ischemic injury, you know, someone who drowned or had a heart attack, I think is quite far away," he said. "The much more promising short term potential use here is with organ preservation for transplant."

The ethical questions

Some experts also said the study raises ethical questions about the definition of death.

Nita Farahany, a law professor at Duke University who studies the ethical, legal, and social implications of emerging technologies, said the study was "unbelievable, mind blowing."

"We presume death is a thing, it is a state of being," she said. "Are there forms of death that are reversible? Or not?"

Brendan Parent, a lawyer, ethicist, and director of transplant ethics and policy research at New York University's Grossman School of Medicine, said the study raises "tricky questions around life and death."

"By the accepted medical and legal definition of death, these pigs were dead," he said. But, he added, "a critical question is: What function and what kind of function would change things?"

Parent also said OrganEx creates an ethical dilemma between weighing how useful the technology can be for increasing the supply of transplantable organs and how it can be used by doctors on near-death patients.

"We have an ethical duty to prioritize its development for saving lives before we consider the way it can benefit organ transplant," he said. (Kolata, New York Times, 8/3; Marcus, Wall Street Journal, 8/3; Hunt, CNN, 8/3)