The first patient to receive a heart transplant from a genetically modified pig died two months after the operation. The Maryland School of Medicine hospital, where the experimental surgery was performed, announced that David Bennett, 57, died on March 8, after his condition had started to deteriorate a few days earlier.
Doctors did not reveal the exact cause of Bennett’s death. However, not only organ rejection, but also infection and other complications can be fatal for heart transplant patients.
Performing the surgery, Dr. Bartley Griffith said in a statement: “The loss of Mr. Bennett has devastated us. He proved himself to be a brave and noble patient who fought to the end.”
His son, David Bennett Jr, who bears the same name as his father, thanked the hospital that offered this experiment as their last hope, and said he hopes this initiative will help efforts to end organ shortages.
In a statement released 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 has been involved in this historic effort. We hope this story will be the beginning of hope, not the end.”
Doctors have been working for years to use animal organs in transplant surgeries. Bennett, of Hagerstown, Maryland, was a candidate for this newest venture, as he was bedridden and on life support and faced inevitable death as he was unfit for a human heart transplant.
After the transplant surgery on January 7, Bennett’s son told the Associated Press news agency that his father knew there was no guarantee it would work.
Previous animal-to-human organ transplant attempts have largely been unsuccessful because patients’ bodies quickly rejected the animal organ. This time, surgeons at the Maryland School of Medicine used a heart from a genetically modified pig. By eliminating the pig genes that trigger organ rejection, the scientists added human genes to help the body accept the heart.
The pig’s heart was working in the first weeks after surgery, and the hospital released periodic updates showing Bennett’s slow recovery. In fact, footage of Bennett watching the American Football Championship from his hospital bed while working with his physiotherapist was published last month.
Bennett became the longest surviving animal-to-human transplant patient with a genetically engineered pig heart. Earlier in 1984, a baby lived 21 days with a baboon heart.
Director of the University of Maryland’s animal-to-human transplant program, Dr. “During Bennett’s treatment, we gained invaluable insight into learning that the genetically modified pig heart can work in the human body when the immune system is sufficiently suppressed,” said Mohammed Mohiuddin.
The need for another organ source for transplants worldwide is enormous. In the USA alone, a record was broken with more than 41,000 transplants, of which 3,800 were heart transplants, last year. But more than 106,000 people are on the national waiting list. Every year, thousands of people die before they can get an organ; Thousands of people are not even included in the list because they are too ill to comply with the transplant conditions.
The U.S. Food and Drug Administration had authorized the Maryland School of Medicine’s experimental surgery under emergency rules. Bennett, who is a patient with advanced heart failure, was not suitable for treatments that required continued medication, such as an artificial heart device or a heart transplant, because his doctors had an irregular heartbeat and had not followed medical instructions in the past.
The question now is whether scientists have gained enough knowledge to persuade the Food and Drug Administration to allow clinical trials after Bennett. Experimental surgeries planned in the near future are likely to be performed with an organ such as the kidney, which, if unsuccessful, will not be immediately fatal.
Twice last fall, surgeons at New York University obtained permission from families to monitor the work of deceased individuals by temporarily connecting a gene-edited pig kidney to blood vessels outside the body, before ending life support.
Surgeons at the University of Alabama at Birmingham went a step further and transplanted a pair of genetically modified pig kidneys into a brain-dead person, step-by-step rehearsal of a surgery they hoped to try on later living patients.
Pigs have long been used in medicine for human health, including pigskin transplants and pig heart valve implantation. But transplanting whole organs is much more complicated than using highly processed tissue. The genetically modified pigs used in these experiments were supplied by Revivicor, a subsidiary of United Therapeutics, one of several biotech companies working to develop pig organs suitable for potential human transplantation.