University of Maryland Doctors Perform a Successful Xenotransplantation of a Humanized Pig’s Heart into a Human Patient

Doctors in Baltimore, Maryland, have successfully performed a unique xenotransplantation procedure. A genetically modified pig heart was transplanted into a 57-year-old man suffering from terminal heart disease.

Pig’s Heart Transplant. Image Courtesy of University of Maryland School of Medicine

A Chance to stay alive

David Bennett, a 57-year-old resident of Maryland was doomed to live in a hospital bed due to a serious heart condition. His condition made him ineligible for a heart transplant, and his arrhythmias meant that he cannot receive an artificial heart. Doctors at the University of Maryland have offered him an experimental last resort: a genetically modified pig’s heart. This was an operation that has never before been performed on a patient with terminal heart disease.

David Bennett agreed: “It was either die or have this transplant. I want to live. I know it’s a gamble, but it’s my last choice,” he said. The operation took place on January 7, 2022, and according to the University of Maryland press release reporting this amazing surgery, David Bennett is doing well three days after the transplant.

A humanized pig heart transplant

The transplanted heart came from a genetically modified pig. A total of 10 genetic modifications were made to maximize the chances of a successful transplant: three genes were removed to limit rejection, six human genes were added to make the heart more immune, and one gene was added to limit the growth of pig tissue. The heart was removed from the animal by the same surgeons who performed the transplant and placed in a special box that kept it alive ex vivo before the transplant.

Preliminary animal studies have shown that a heart from a pig transplanted into a monkey can still function after three years. Based on this data and David’s desperate case, the FDA approved this experiment. There are still many unknown factors surrounding xenotransplants before they become routine procedures. Do the benefits to patients outweigh the risks? “The success of the procedure provided valuable information to help the medical community improve this potentially life-saving method in future patients,” said Muhammad M. Mohiuddin, one of the surgical professors who performed the transplant.

Final thoughts

Last year it was a pig’s kidney that was transplanted into a human and now it is a pig’s heart. If these types of surgeries become routine many people that would have died waiting to get a transplant now can survive. This would be one of the most important breakthroughs in medicine.