All patients who have received pig organs have now died

All four patients who received pig organs to replace their diseased organs have now died, though researchers involved in these transplants say they will keep trying to improve this alternative source of organs.

Lisa Pisano, the fourth xenotransplantation patient and second to receive a pig kidney, died Sunday. The other three patients died within two months of transplantation.

Pisano received the kidney on April 12 . It had to be removed on May 29, after it failed because of medications that supported Pisano's blood pressure, Dr. Robert Montgomery, who helped lead her care team at NYU Langone Health, said in a statement. She was on dialysis until she died.

Pisano, 54, of New Jersey, had also received an LVAD heart pump to support her weakened organ and was very ill when she agreed to the experimental double surgeries in April.

Researchers have been trying for years to gene-edit animals to make them suitable for organ transplants.

More than 100,000 Americans are waiting for an organ to become available. Organs typically become available following a tragedy to another family. Many others, like Pisano, will never qualify for a transplant waitlist because they have been deemed too ill or otherwise not a good candidate for a transplant.

The hope is that pigs that have been gene-edited to make their organs less likely to be rejected by the human immune system can supplement human organs. For decades, though, animal research has faced repeated problems, advancing at a painfully slow pace.

The first trials using pig organs in people, two heart transplants at the University of Maryland in 2022 and 2023 , followed by a kidney transplant at Massachusetts General Hospital at Pisano at NYU in April, were supposed to turbocharge the field. However, none of the patients survived more than two months with their pig organs.

Still, researchers are committed to continuing .

"Lisa's contributions to medicine, surgery, and xenotransplantation cannot be overstated," said Montgomery, director of the NYU Langone Transplant Institute. "Her bravery gave hope to thousands of people living with end-stage kidney or heart failure who could soon benefit from an alternative supply of organs."

Karen Weintraub can be reached at kweintraub@usatoday.com.

This article originally appeared on USA TODAY: All patients who have received pig organs have now died