Breakthrough as scientists successfully revive dead pig organs

Scientists have restored blood circulation and other cell functions in pigs an hour after their death using new technology that delivers cell-protective fluid to organs and tissues.

The findings, published on in the journal Nature, could help extend the health of human organs during surgery and also make more transplants possible.

While the scientists, including those from Yale School of Medicine in the US, did not find any electrical brain activity associated with normal brain function following the procedure, the research confounds conventional wisdom on life and death.

“This study demonstrates that our social convention regarding death, ie, as an absolute black and white end is not scientifically valid,” said Sam Parnia, director of critical care and resuscitation research at New York University Grossman School of Medicine.

“By contrast, scientifically, death is a biological process that remains treatable and reversible for hours after it has occurred,” Dr Parina, who was not involved in the study, said.

Just minutes after the final heartbeat, blood circulation begins to stop and cells in the body start to die due to lack of oxygen, and chemical changes that harm tissues and organ function begin.

However, the new study suggests a cascading cell failure on such a massive and permanent level doesn’t happen so quickly.

“All cells do not die immediately, there is a more protracted series of events. It is a process in which you can intervene, stop, and restore some cellular function,” David Andrijevic, study co-lead author at Yale School of Medicine said.

In the research, scientists applied a new technology consisting of a perfusion device similar to heart-lung machines – which do the work of the heart and lungs during surgery – and an experimental fluid containing compounds that can promote cellular health and suppress inflammation throughout the pig’s body.

They induced cardiac arrest in anesthetised pigs and treated them with the new technology, named OrganEx, an hour after death.

Researchers found that some key cellular functions were active in many areas of the pigs’ bodies, including in the heart, liver, and kidneys, and that some organ function had been restored six hours after treatment with OrganEx.

The study also found evidence of electrical activity in the heart, which retained the ability to contract, after treatment with the device.

“We were also able to restore circulation throughout the body, which amazed us,” Nenad Sestan, professor of comparative medicine, genetics, and psychiatry at Yale and co-author of the study, said.

“Under the microscope, it was difficult to tell the difference between a healthy organ and one which had been treated with OrganEx technology after death,” Zvonimir Vrselja, another author of the study, added.

Scientists said they were “especially surprised” to observe involuntary and spontaneous muscular movements in the head and neck areas when they evaluated the treated animals, indicating the preservation of some motor functions.

However, researchers said additional studies are necessary to understand the restored motor functions.

They added that rigorous ethical review from other scientists and bioethicists is also required.

“This is a truly remarkable and incredibly significant study. It demonstrates that after death, cells in mammalian organs (including humans) such as the brain do not die for many hours. This is well into the post-mortem period,” Dr Parnia said.

While the research may lead to more lives saved via organ transplantations each year, the critical care medicine professor said the new method could also find use to preserve organs in those who have died, but in whom the underlying cause of death remains treatable.

“Today, this would include athletes who die suddenly from a heart defect, people who die from drowning, heart attacks or massive bleeding after trauma (such as car accidents),” he explained.

“This will provide time for doctors to fix the underlying condition (such as a blocked blood vessel in the heart that had led to a massive heart attack and death, or repair a torn blood vessel that had led to death from massive bleeding after trauma), restore organ function and bring such people back to life many hours after death,” Dr Parnia added.

Researchers say the findings also pose ethical questions on when a person may be conclusively pronounced dead.

“There is a challenging ethical issue in determining when radical life support is just futile, and as technology advances we may find more ways of keeping bodies alive despite being unable to revive the person we actually care about,” Anders Sandberg, senior research fellow at the Future of Humanity Institute, University of Oxford, said.

“Much work remains to find criteria for when further treatment is futile, and also in how to get people back from the brink,” Dr Sandberg, who was also not involved in the study, added.