In a medical first, doctors have transplanted a pig’s heart into a patient, in a last-ditch effort to save a patient’s life. And three days after the highly experimental surgery, a Maryland hospital said on Monday that the patient was doing well.
While it is too early to know whether the operation will actually work, it is a step in the decades-long quest to one day use animal organs for life-saving transplants. Doctors at the University of Maryland Medical Center near Baltimore say the transplant has shown that the heart of 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, unfit for a human heart transplant and had no other choice, his son told the Associated Press. told.
“Either it died or it transplanted. I want to live,” Bennett said the day before the surgery, according to a statement provided by the University of Maryland School of Medicine. “I know it’s a shot in the dark, but it’s my last choice.”
There is a severe shortage of donated human organs for transplant, forcing scientists to figure out how to use animal organs instead.
‘Endless supply’ of organs if animal transplants work
More than 3,800 heart transplants were performed in the US last year — a record number — according to the United Network for Organ Sharing (UNO), which oversees the country’s transplant system.
The numbers are increasing in Canada as well. In 2019, more than 3,000 organ transplant procedures were performed in total, a 42 percent increase since 2010, according to the latest data from the Canadian Organ Replacement Register (CORR) – an all-Canadian information system for organ failure in Canada.
“If it works, there will be an endless supply of these organs for afflicted patients,” said Dr. Muhammad Mohiuddin, scientific director of the animal-to-human transplant program at the University of Maryland.
But prior attempts at such transplantation – or xenotransplantation – have failed, mainly because the patients’ bodies rapidly rejected the animal organs. Notably, in 1984, Baby Fay, a dying infant, lived 21 days with a baboon heart.
The difference this time: Surgeons in Maryland used the heart of a pig that had been gene-edited to remove a sugar in its cells that is responsible for that hyper-fast organ rejection.
“The big issue with the story is that with transplants, the issue is always that you need to find a match, and your body will very quickly reject a heart of another species,” said Montreal-based cardiologist Dr Christopher Lebos. told CBC News in an email exchange.
“What’s interesting to me is that they were able to create a genetically modified pig that suppressed the cell markers that would lead to rejection. That’s very interesting, moving forward.”
“I think you can characterize this as a watershed event,” UNOS chief medical officer Dr. David Klaasen said of the Maryland transplant.
Still, Klaasen cautioned that this is only the first tentative step in finding out whether this time around, xenotransplantation might eventually work.
The Food and Drug Administration, which oversees xenotransplantation experiments, allowed the surgery under “compassionate use” emergency authorization — available when a patient with a life-threatening condition has no other option.
‘Really remarkable success’
Last September, researchers in New York conducted an experiment that suggested genetically modified pigs could hold promise for animal-to-human transplants. Doctors temporarily attached a pig kidney to a dead human body and watched it begin to function.
The Maryland transplant takes it to the next level, said Dr. Robert Montgomery, who led that experiment at NYU Langone Health in New York City.
“This is truly a remarkable success,” he said in a statement. “As a heart transplant recipient myself with a genetic heart disorder, I am thrilled by this news and the hope it gives to my family and other patients who will eventually survive this breakthrough.”
It will be important to share the data collected from this transplant before the option is opened to more patients, said Karen Maschke, a research scholar at the Hastings Center in Garrison, NY, who specializes in ethics and policy recommendations for the first clinical trials. helping to develop. Grant from the National Institutes of Health.
“Without this information it would not be appropriate to hasten animal-to-human transplantation,” Maschke said.
The surgery, which took place last Friday at a Baltimore area hospital, took seven hours.
David Bennett Jr. said of his father, “He feels the magnitude of what was done and he really understands the importance of it.” “He couldn’t survive, or he could last a day, or he could last a few days. I mean, we’re in the unknown at the moment.”