A grandmother died on Sunday, months after she received a combined mechanical heart pump and gene-edited pig kidney transplant, according to the hospital that performed the surgeries. 

Lisa Pisano, 54, was suffering from heart and kidney failure before the surgeries and was ineligible for a human transplant. She received the heart pump, called an LVAD, on April 4 and the pig kidney transplant on April 12. In May, 47 days after the transplant, doctors removed the genetically engineered organ because it was interfering with her blood flow. 

“Lisa’s contributions to medicine, surgery, and xenotransplantation cannot be overstated,” Dr. Robert Montgomery, director of the NYU Langone Transplant Institute, said in a statement Tuesday. “Her legacy as a pioneer will live on and she will forever be remembered for her courage and good nature.”

Before the two procedures, Pisano faced heart failure and end-stage kidney disease that required routine dialysis. 

“I was pretty much done,” Pisano told CBS News chief medical correspondent Dr. Jon LaPook, who is also a professor at NYU Langone, in an April interview. “I couldn’t go up the stairs. I couldn’t drive. I couldn’t play with my grandkids. So when this opportunity came to me I was taking it.” 

After the procedures, she told LaPook she felt “great today compared to other days.”

Around 104,000 people in the U.S. are on the waiting list for a transplant, with more than 80% of those patients waiting for a kidney, NYU Langone said. Across the U.S., nearly 808,000 people are suffering from end-stage kidney disease, but only about 27,000 received transplants last year.

Pisano’s implant was only the second transplant of a gene-edited pig kidney into a living person, the hospital said. Surgeons had previously tested a pig kidney transplant on brain-dead patients.

In March, surgeons at Massachusetts General Hospital in Boston transplanted a pig kidney into 62-year-old Rick Slayman. He died in May. The hospital said there was no indication his death was a result of the transplant.

Montgomery said Pisano’s bravery in trying a genetically modified pig kidney gave hope to people awaiting transplants about the possibility of an alternative supply of organs. 

“Lisa helped bring us closer to realizing a future where someone does not have to die for another person to live,” the doctor said.

Historically, animal-to-human transplants have not been compatible, Montgomery told LaPook in 2021 after a transplant. 

“When you cross species with a transplant and it happens immediately, humans have preformed antibodies circulating in their blood,” he said. “And so when you put an organ from a pig into a human, it’s immediately rejected.”

The pig kidney Pisano received was genetically engineered to “knock out” the gene responsible for the production of a sugar known as alpha-gal, NYU Langone said in April. Studies have shown that removing the alpha-gal can prevent the reaction that causes an immediate rejection of the transplanted organ. 

“By using pigs with a single genetic modification, we can better understand the role one key stable change in the genome can have in making xenotransplantation a viable alternative,” Montgomery said in a statement earlier this year. “Since these pigs can be bred and do not require cloning like more-complex gene edits, this is a sustainable, scalable solution to the organ shortage. If we want to start saving more lives quickly, using fewer modifications and medications will be the answer.”