The “resuscitation” of dead pigs, promise of progress and source of questions

Scientists succeeded on Wednesday in reviving blood circulation and the functioning, for a few hours, of cells in the bodies of deceased pigs. This medical feat is the promise of significant progress on the surgical front. But if science has never resurrected pigs, a phenomenon observed during the experiment leaves the door open to dizzying potential.

A story of living pigs. Yet cold as death, pigs were brought back to a form of life, their organic functions restored, Wednesday, August 3, by American researchers.

Already in 2019, these same scientists had already stunned the medical world by managing to restore cell function in the brains of pigs, a few hours after their decapitation.

In their latest research, published Wednesday in the journal Nature, the team took the bet even further, extending this technique to the entire body of the animal.

They caused heart attacks in anesthetized pigs, which stopped blood flow and deprived their cells of oxygen – without oxygen, mammalian cells die.

After an hour, they injected the dead bodies with a liquid containing the pigs’ blood (taken from them while they were alive) and a synthetic form of hemoglobin – the protein that carries oxygen in red blood cells. As well as drugs that protect cells and prevent the formation of blood clots.

Blood began to flow again and many cells started functioning again, including in vital organs like the heart, liver and kidneys, for the next six hours.

Enrich the bank of transplantable organs

Good news for surgery: vital organs could be “reanimated” for a transplant. Because until now, beyond a few minutes of circulatory arrest, the organs could no longer be transplanted, explains Doctor Jean-Etienne Bazin, head of the perioperative medicine center at the Clermont-Ferrand University Hospital.

“However, the cells of the pigs were working hours later, when they should not have been working,” said Nenad Sestan, lead author of the study and researcher at Yale University, during a press briefing.

OrganEx – this is the name of this technique – “could thus enable us to enrich the bank of transplantable organs”, rejoices Jean-Etienne Bazin. This could potentially save the lives of people awaiting a transplant.

What is death?

For Sam Parnia, from the department of medicine at the same university, this “really remarkable” study also shows that “death is a biological process that is treatable and reversible hours later”.

So much so that the medical definition of death may need updating, said Benjamin Curtis, a philosopher specializing in ethics at Britain’s Nottingham Trent University.

“Given this study, many processes that we thought were irreversible would not be,” he told AFP. “And, according to the current medical definition of death, a person might not be truly dead for hours,” with some processes continuing for a time beyond the cessation of bodily functions.

Philippe Bizouarn, anesthetist-resuscitator at the Nantes University Hospital, is in no way surprised: “The death of a person is not that of his cells”.

In the Arrée mountains, where this Breton was during the fires that ravaged the forests of his childhood, “a green grass appeared under the ashes. Like the cells in an inanimate body, seeds have come back to life under the remains of an entirely calcined vegetation”, explains the doctor in an effort to popularize.

Too early for philosophy?

But “beware of fantasies,” warns Dr. Bizouarn, for whom these pigs were not “brought back to life”. “Let’s say rather that we managed to restore their organs to their functions”. In short, for the anesthesiologist, science does not raise the dead.

But “as usual, this experience will be taken over by transhumanist groups such as Google X Lab”, sighs Philippe Bizouarn.

Indeed, barely revealed to the public, the experience already raises a myriad of ethical and even philosophical questions.

Even if science fiction helps to “ask us the right bioethical questions”, these, in this case, have no place for the doctor to date: Among those who fuel these controversies, many have, according to him, “no idea of ​​what is happening in medical reality”.


Far from sensationalism, however, a reaction noted during the pig experiment raises more questions than it answers: a very large majority of the animals made powerful movements with their head and neck, according to the account of Stephen Latham, one of the study’s authors. “It was quite surprising to the people in the room,” he told reporters.

If the origin of these movements remains unknown, the scientist assured that at no time had electrical activity been recorded in the brains of the pigs – thus excluding, a priori, a recovery of consciousness.

These head movements are nevertheless “a major concern”, believes Benjamin Curtis, because recent research in neuroscience has suggested that “conscious experience can continue even when electrical activity in the brain cannot be measured”.

And doctor Jean-Etienne Bazin to explain another variable: during the experiment, the anesthesia or hypothermia of the animals could inhibit the electrical activity, and thus distort the diagnosis.

Hence an unresolved question, continues the doctor-professor: how to interpret the movements of these pigs? Was it “simply” the fruit of the motor stimuli that the spinal cord “automatically” sends, or the conscious orders of their brains, which would have woken up? For this scientist, not being able to absolutely invalidate this last eventuality, that is what is “extraordinary”.

His colleague, Philippe Bizouarn, understands the hopes that such potentiality can generate, but “deep down, fortunately, death is before us, otherwise we would not be able to live,” the doctor philosophizes.

To be reborn or not to be reborn? That may not be the question.


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