May 17, 2022

New York surgeons successfully attached a kidney developed in a genetically modified pig to a human patient and discovered that the organ functioned normally, a scientific milestone that could one day result in a massive new supply of organs for critically ill people.

Although many uncertainties remain regarding the long-term effects of the transplant, which involved a brain-dead patient who was monitored for only 54 hours, specialists in the field acknowledged the procedure was a watershed moment. Because the patient was a registered organ donor and the organs were unsuitable for transplantation, the patient’s family agreed to allow research to test the experimental transplant process.

“We need to know more about the longevity of the organ,” said Dr. Dorry Segev, Professor of transplant surgery at Johns Hopkins School of Medicine who was not involved in the research. Nevertheless, he said: “This is a huge breakthrough. It’s a big, big deal.”

The pig’s kidney, which is attached to the blood vessels in the upper leg outside the abdomen, began to function almost immediately, producing urine and the waste product creatinine, according to Dr. Robert Montgomery, the Director of NYU Langone’s Transplant Institute. He performed the procedure in September.

“It was better than I think we even expected,” he said. “It just looked like any transplant I’ve ever done from a living donor. A lot of kidneys from deceased people don’t work right away and take days or weeks to start. This worked immediately.”

Although the organ was not put into the body, specialists cautioned that complications with so-called xenotransplants from animals such as monkeys and pigs typically arise when human blood starts to flow through pig veins.

Researchers have long sought to generate humane organs in pigs. A regular supply of organs, which might ultimately include hearts, lungs, and livers, would provide a lifeline to the more than 100,000 Americans currently on transplant waiting lists, including 90,240 who require a kidney. Each day, twelve people on waiting lists die.

A total of 39,717 people in the United States underwent an organ transplant last year, with the majority, 23,401, receiving kidneys, according to the United Network for Organ Sharing.

“Genetically engineered pigs could potentially be a sustainable, renewable source of organs — the solar and wind of organ availability,” Montgomery added.