The pig has been dead for an hour. But with a new device that pumps a special fluid through the sow’s body, the function of her vital organs is restored. The damage that occurs due to the lack of oxygen is thus reversed.
Researchers at the Yale School of Medicine in the US reveal an unexpected ability of vital organs to recover from a long period without oxygen without being cooled. The technique could make more organs available for transplants. The research appeared this Wednesday in Nature.
As soon as blood flow stops in a human or other mammal, processes begin in the body that quickly lead to cell death and organ damage. The removal of organs for transplantation therefore has to be done quickly, and that is often not possible. The waiting lists for transplants are long. Scientists are therefore looking for ways to make more organs available.
For example, individual organs, such as the heart, kidneys, lungs and liver, can be kept alive outside the body for a while and even improved.
Device with artificial blood
Three years ago, the same researchers released BrainEx, an artificial blood device that could restore the activity of some cells in pig brains that were plugged in four hours after slaughter. Now they have converted that system in such a way that they can regenerate a complete pig body with it: OrganEx.
Also read: Brain cells in dead pig brain reactivated
The researchers put a pig under anesthesia and then stopped the heart. Then they let the animal lie for an hour, unrefrigerated. They then connected their device to the circulatory system through a vein and artery in the groin. The system consists of pumps, sensors, reservoirs and filters that are connected to each other via hoses. The fluid pumped through the dead pig’s blood vessels contained Hemopure, a synthetic form of the oxygen-binding protein hemoglobin found in real blood, as well as tissue protectants, antibiotics and anticoagulants.
The Americans compared their system to an existing machine for keeping bodies alive: a heart-lung machine. With this, blood is pumped out of the body, stripped of carbon dioxide and supplied with oxygen, and pumped back again. This machine is used when a patient’s heart or lungs temporarily malfunction, for example during a heart transplant or severe pneumonia. Organs and tissues then remain intact as much as possible.
The researchers show that after six hours of running their OrganEx manages the flow of artificial blood in organs better than the heart-lung machine, and that the treatment improves the cell structure of all kinds of tissues and organs, including the heart, lungs, kidneys. , and even in the brain. There was no measurable general electrical activity in the brain, which is not sufficient for normal brain function such as consciousness. In the pigs’ kidneys, liver and heart, the treatment activates the production of specific substances and enzymes that are necessary for the repair of damage in cells and in the repair of organs.
Damaged beyond repair
Robert Porte, professor of surgery at the University Medical Center Groningen and transplant expert, praises the study. “Half of the organs for transplantation in the Netherlands come from donors who are brain dead – their brains no longer have electrical activity, but thanks to a ventilator their heart continues to beat until the moment of removal. The other half comes from donors whose brains are so irreparably damaged that further treatment is pointless. After stopping the ventilator, their heart will stop on its own. It can take up to 30 minutes after death before the organs can be cooled on ice, all this time there is oxygen deficiency in the warm state.”
In the Netherlands and seven other European countries, such a deceased person has been placed on a heart-lung machine for a few years now, so that the organs are damaged as little as possible. “We can improve that treatment with these new insights.”
Parts of the technology, for example the liquid with Hemopure, could one day also be used by doctors to better save people after a stroke or cardiac arrest, says Porte. “It may therefore also be that fewer donors become available as a result of these improvements.”
A version of this article also appeared in the newspaper of August 4, 2022