US surgeons transplant pig heart into human patient as medical first

US surgeons transplant pig heart into human patient as medical first

In a medical first, doctors transplanted a pig’s heart into a patient, in a last-ditch effort to save his life. And three days after the highly experimental surgery, a Maryland hospital said on Monday that the patient was doing well.

While it’s too early to know if the surgery will really work, it marks a milestone in the decades-long quest to one day use animal organs for vital transplants. Doctors at the University of Maryland Medical Center near Baltimore say the transplant has shown that a heart from a genetically modified animal can function in the human body without immediate rejection.

The patient, David Bennett, 57, knew there was no guarantee the experiment would work, but he was dying, ineligible for a human heart transplant and had no other option, his son said at the Associated Press.

“It was either die or do this transplant. I want to live,” Bennett said a day before the operation, according to a statement provided by the University of Maryland School of Medicine. “I know it’s a hit in the dark, but it’s my last choice.”

There is a huge shortage of human organs donated for transplantation, leading scientists to try to figure out how to use animal organs instead.

‘Endless supply’ of organs if animal transplants work

Last year in the United States, there were just over 3,800 heart transplants – a record number – according to the United Network for Organ Sharing (UNO), which oversees the country’s transplant system.

The numbers are also on the rise in Canada. In 2019, more than 3,000 organ transplants in total were performed, an increase of 42% since 2010, according to the latest data from the Canadian Organ Replacement Registry (CORR), a pan-Canadian information system on organ replacement. organ failure in Canada.

“If this works, there will be an inexhaustible supply of these organs for patients who are in pain,” said Dr. Muhammad Mohiuddin, scientific director of the animal-to-human transplant program at the University of Maryland.

But previous attempts at such transplants – or xenotransplants – have failed, in large part because patients’ bodies quickly rejected animal organs. Notably, in 1984, Baby Fae, a dying infant, lived 21 days with a baboon heart.

The difference this time: surgeons in Maryland used a pig’s heart that had undergone a genetic modification to eliminate a sugar in its cells which is responsible for this hyper-rapid organ rejection.

Dr Bartley Griffith (left) with patient David Bennett, who underwent a heart transplant from a pig, a world first. (Provided by the University of Maryland School of Medicine.)

“The big problem with the story is that with transplants the problem is always that you have to find a match, and your body will reject a heart of another species very quickly,” said Dr. Christopher Labos, cardiologist based. to Montreal. CBC News in an email exchange.

“What interests me is that they were able to make a genetically engineered pig that removed cell markers that would lead to rejection. It’s very interesting going forward.”

“I think you can characterize it as a watershed event,” UNOS chief medical officer Dr David Klassen said of the Maryland transplant.

Still, Klassen warned that this was only a tentative first step in determining whether this time around, xenotransplantation might finally work.

The Food and Drug Administration, which oversees the xenotransplantation experiments, authorized the surgery under what’s called an emergency “compassionate use” authorization – available when a patient with a life-threatening illness does not. has no other options.

“A truly remarkable breakthrough”

Last September, researchers in New York performed an experiment suggesting that genetically modified pigs may hold promise for animal-to-human transplants. Doctors temporarily attached a pig kidney to a deceased human body and watched it begin to function.

The Maryland transplant takes that to the next level, said Dr. Robert Montgomery, who led the experiment at NYU Langone Health in New York City.

“It’s a really remarkable breakthrough,” he said in a statement. “As a heart transplant recipient myself with genetic heart disease, I am delighted with this news and the hope it gives to my family and other patients who will ultimately be saved by this breakthrough. . “

It will be crucial to share the data collected from this transplant before opening the option to more patients, said Karen Maschke, a researcher at the Hastings Center in Garrison, NY, who helps develop ethical and policy recommendations for patients. first clinical trials under a grant from the National Institutes of Health.

“Rushing into animal-to-human transplants without this information would not be advisable,” Maschke said.

The operation last Friday lasted seven hours at the Baltimore area hospital.

“He realizes the magnitude of what has been done and he truly realizes the significance of it,” David Bennett Jr. said of his father. “He couldn’t live, or he could last a day, or he could last a few days. I mean, we’re in the dark at this point.”

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