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 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, a 57-year-old handyman from Maryland, knew there was no guarantee the experiment would work, but he was dying, ineligible for a human heart transplant and had no d ‘other option, her son told The Associated Press.
“It was either die or do this transplant. I want to live. I know it’s a blow in the dark, but it’s my last choice,” Bennett said a day before the operation, according to a statement. provided by the University of Maryland School. of Medicine.
On Monday, Bennett was breathing on his own while still connected to a heart-lung machine to help his new heart. The next few weeks will be critical as Bennett recovers from the operation and doctors closely monitor the condition of his heart.
There is a huge shortage of human organs donated for transplantation, leading scientists to try to figure out how to use animal organs instead. Last year there were just over 3,800 heart transplants in the United States, a record number, according to the United Network for Organ Sharing, which oversees the nation’s transplant system.
“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 the animal organ. 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 remove a sugar in its cells that is responsible for this hyper-rapid organ rejection. Several biotechnology companies are developing organs from pigs for human transplantation; the one used for Friday’s operation was from Revivicor, a subsidiary of United Therapeutics.
“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 such experiments, authorized the surgery under what is known as an emergency “compassionate use” authorization, available when a patient with a life-threatening illness has failed. no other options.
It will be crucial to share the data collected from this transplant before expanding it to more patients, said Karen Maschke, a researcher at the Hastings Center, who is helping develop ethical and policy recommendations for early clinical trials in the framework. a grant from the National Institutes of Health.
“Rushing into animal-to-human transplants without this information would not be advisable,” Maschke said.
Over the years, scientists have gone from primates to pigs, tinkering with their genes.
Last September, researchers in New York performed an experiment suggesting that these types of 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 their experience to the next level, said Dr. Robert Montgomery, who led this work at NYU Langone Health.
“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.”
The operation last Friday lasted seven hours at a hospital in Baltimore. Dr Bartley Griffith, who performed the operation, said the patient’s condition – heart failure and irregular heartbeat – made him ineligible for a human heart transplant or a heart pump.
Griffith had transplanted pig hearts into around 50 baboons in five years, before offering Bennett the option.
“We learn a lot every day with this gentleman,” Griffith said. “And so far we’re happy with our decision to go ahead. And so is he: big smile on his face today.”
Pork heart valves have also been used successfully for decades in humans, and Bennett’s son said his father received one about a decade ago.
As for the heart transplant, “He realizes the magnitude of what has been done and he really realizes the importance of it,” said David Bennett Jr .. “He couldn’t live, or it could last a long time. day, or it could last a few days. I mean, we’re in the dark at this point. “
AP medical writer Lauran Neergaard contributed.
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