Tests performed on deceased patients could help refine future trials on living patients.
New York researchers have transplanted two pig hearts into brain-dead patients over the past month, the latest chapter in a long quest to save human lives with animal organs.
The experiments unveiled on Tuesday come after the unprecedented but unsuccessful attempt to use a pig's heart to save a Maryland man, a sort of dress rehearsal before another attempt with a living patient.
Among the lessons: practicing on the dead is important
We learned so much with the first (transplant) that the second was so much better , said Dr. Nader Moazami, who led the interventions at NYU Langone Health.
You gasp when the pig's heart starts beating in a human body, he added.
This time, Dr. Moazami's team imitated a regular heart transplant. Once last month and once last week, researchers visited a facility with genetically modified pigs, removed the hearts, put them on ice, and then transported them hundreds of miles to New York.
They used special methods to make sure no unwanted animal viruses were present, before transplanting the hearts to the two patients, a veteran who had a long history of heart disease and a New -Yorker who had already received a new heart.
They then proceeded with a battery of tests more intense than a living patient could tolerate – including frequent organ biopsies – before doctors disconnected the systems that were keeping them alive.
< p class="e-p">The U.S. Food and Drug Administration is already considering allowing a select number of Americans who need a new organ to volunteer for rigorous studies of the use of hearts or kidneys of pigs. NYU Langone is one of three transplant centers planning clinical trials, and a meeting to that end is scheduled with the FDA in August.
Tests performed on deceased patients could help refine future trials on living patients, said Dr. David Klassen of the United Network for Organ Sharing, who oversees the transplant system in the United States.
This is an important step, says Dr Klassen, who wonders if the functioning of organs in a donated body could now be studied for science for about a week instead of just three days .
One of the deceased patients, Lawrence Kelly, had suffered from heart disease for most of his life and he would be so happy to know that his contribution to this research will help people like him in the future, reporters told Tuesday. his longtime partner, Alice Michael.
Animal-to-human transplants, what researchers call a xenograft, have been attempted for decades without success, since humans' immune systems almost instantly attack foreign tissue. But now pigs are being genetically engineered to make their organs more closely resemble those of humans, raising hopes that they may one day fill organ shortages. p>
More than 100,000 people are waiting for a new organ in the United States, primarily a kidney, and thousands die each year before they are called.
The most ambitious attempt to date occurred in January, when doctors at the University of Maryland Medical Center transplanted a pig's heart into a 57-year-old man. David Bennett survived for two months, demonstrating that a xenograft is at the very least possible.
Tests failed to detect the presence of an animal virus, however. in the organ. It is not yet known whether this played a role in Mr. Bennett's heart failure, the researchers recently wrote in the New England Journal of Medicine.
Another NYU Langone physician, Dr. Robert Montgomery, explained that careful experiments on deceased patients are essential to identify the best methods in a setting where the patient's life is not in danger.< /p>
It's not once and that's it, he said. We have years to learn what is important and what is not.