David Bennett and members of the surgical team at the University of Maryland School of Medicine in Baltimore, January 7, 2022. AP
David Bennett, a 57-year-old American who lived for two months with a genetically modified pig heart, died on Tuesday, March 8. “His condition began to deteriorate a few days ago. When it became apparent that he would not recover, he was given palliative care. He was able to communicate with his family in the last hours of his life,” according to a press release from the University Hospital of Maryland, where this xenograft (transplantation from another animal species) was performed, the first of its kind in the world. with a genetically modified heart.
See also: The first patient who received a pig heart transplant died two months after the operation
End-stage heart failure, David Bennett was hospitalized in October 2021 and was initially treated with what is known as an ECMO (for extracorporeal membrane oxygenation) procedure: an extracorporeal circulation circuit with a membrane to provide blood oxygenation and CO2 removal.
This patient, not eligible for a conventional heart transplant but also for an artificial heart pump system, gave his consent to an experimental porcine heart transplant. The procedure, urgently authorized by the Food and Drug Administration (U.S. health authorities) out of compassion, was performed on January 7 by surgeons Bartley Griffith and Muhammad Mohiuddin.
Heart named Uhart
To make this heart, called Uheart, US firm Revivicor modified ten genes from a pig organ using genome editing techniques. Three genes responsible for the rapid rejection of pig organs by humans have been knocked out. In addition, six human genes responsible for the immune susceptibility of pig hearts were inserted into the genome. Finally, an extra gene was removed from the animal to prevent overgrowth of pig heart tissue. The patient then received immunosuppressive treatment, also experimental.
Announced days late, this first study was widely publicized and hailed as a feat by the medical world. The patient’s survival of more than seventy-two hours with a functioning heart effectively meant that there was no hyperacute organ rejection, one of the major risks of cross-species transplants, along with infections.
The first attempts at xenotransplantation began in the early 20th century with a monkey kidney transplant. In the 1980s in California, a little girl of about 1 year old – Baby Fairy – received a baboon heart transplant, and three weeks later she died due to the phenomenon of immune rejection.
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