The first person to receive a heart transplant from a pig has died, the Maryland hospital that performed the surgery reported Wednesday, two months after the pioneering procedure.
At the University of Maryland Medical Center, David Bennett, 57, died on Tuesday. Doctors did not specify the reason for death, just stating that his condition had been deteriorating for several days.
Bennett’s son expressed gratitude to the hospital for offering the last-ditch trial. Thereby, noting that the family hoped it would aid future efforts to alleviate the organ scarcity.
In a statement provided by the University of Maryland School of Medicine, David Bennett Jr. said, “We are grateful for every innovative moment, every crazy dream, every sleepless night that went into this historic effort. We hope this story can be the beginning of hope and not the end.”
Xenotransplantation
For decades, doctors have hoped to employ animal organs in life-saving transplants. Bennett, a handyman from Hagerstown, Maryland, was only a candidate for this pig heart transplant because he was on the verge of dying – he was ineligible for a human heart transplant, bedridden, and on life support, and had exhausted all other possibilities.
Bennett’s son told the Associated Press after the operation on Jan. 7 that his father knew there was no assurance it would work.
Attempts at such transplants, known as xenotransplantation, have failed in the past, owing to patients’ bodies’ fast rejection of the animal organ. The Maryland surgeons also utilized a heart from a gene-edited pig, in which scientists removed pig genes that cause hyper-fast rejection and replaced them with human ones to help the body accept the organ.
The pig heart was initially functional, and the Maryland hospital sent periodic reports indicating that Bennett was steadily recovering. Last month, the hospital posted a video of him watching the Super Bowl while working with his physical therapist from his hospital bed.
Bennett lived far longer with the gene-edited pig heart than Baby Fae. Baby Fae was a dying California newborn who lived 21 days with a baboon’s heart in 1984. It was one of the last breakthroughs in xenotransplantation.
Compassionate use
“We are devastated by the loss of Mr. Bennett. He proved to be a brave and noble patient who fought all the way to the end,” Dr. Bartley Griffith, who performed the surgery at the Baltimore hospital, likewise said in a statement.
Other transplant experts praised the Maryland team’s groundbreaking work. They said Bennett’s death shouldn’t derail efforts to find a way to use animal organs to save human lives.
“This was a first step into uncharted territory,” said Dr. Robert Montgomery of NYU Langone Health, a transplant surgeon who received his own heart transplant. “A tremendous amount of information” will contribute to the next steps as teams at several transplant centers plan the first clinical trials.
“It was an incredible feat that he was kept alive for two months and was able to enjoy his family,” Montgomery added.
Another source of organs is desperately in need. Last year, almost 41,000 transplants were performed in the United States, a new high, with roughly 3,800 heart transplants. However, more than 106,000 people remain on the national waiting list, hundreds die each year while waiting for an organ. Many more are never on the list because it is likely too risky.
The spectacular Maryland experiment of pig heart transplant got approval by the Food and Drug Administration. It was under “compassionate use” restrictions for emergencies. Bennett’s doctors diagnosed him with heart failure and an irregular heartbeat, as well as a history of disobeying medical orders. The authorities ruled him ineligible for either a human heart transplant. Thus, it necessitates the usage of immunosuppressive medications or an implanted heart pump, which is the only other option.
Insights
“We have gained invaluable insights learning that the genetically modified pig heart can function well within the human body while the immune system is adequately suppressed,” said Dr. Muhammad Mohiuddin, scientific director of the Maryland university’s animal-to-human transplant program, after hearing about Bennett’s experience.
Any transplant recipient faces the danger of organ rejection, infections, and other problems. Experts hope that the Maryland team publishes the results of Bennett’s body’s reaction to the pig heart as soon as possible in a medical journal.
Furthermore, what data from Bennett’s experience and other recent research with gene-edited pig organs might persuade the FDA to allow a clinical trial; perhaps with a kidney that isn’t immediately lethal if it fails?
Pigs and human medicine
Montgomery’s team at NYU received permission from the families of deceased individuals twice last fall to temporarily link a gene-edited pig kidney to blood arteries outside the body and observe how they functioned before turning off life support. In a step-by-step rehearsal for a surgery, they intend to undertake in living patients later this year. Doctors at the University of Alabama at Birmingham transplanted a pair of gene-edited pig kidneys into a brain-dead man.
Patients may interpret Bennett’s death as implying that xenotransplantation has a short life expectancy. But the experience of one terminally sick individual cannot indicate how well the surgery will ultimately function, according to ethics expert Karen Maschke of The Hastings Center. This will necessitate extensive research involving a large number of patients.
According to Maschke, who is developing ethics and policy recommendations for who should be permissible in the first studies of pig kidneys and what they need to know before volunteering with funding from the National Institutes of Health, transplant centers should start educating their patients about what to expect as this science develops.
Pigs have been in use in human medicine for a long time, including pigskin grafts and pig heart valve implantation. Transplanting complete organs, on the other hand, is far more difficult than using highly processed tissue. Revivicor, a subsidiary of United Therapeutics, donated the gene-edited pigs utilized in these tests. Revivicor is one of several biotech companies competing to generate appropriate pig organs for prospective human transplants.
