An American retiree has become the first person in the world to successfully undergo a pig kidney transplant and survive for almost a year.
Tim Andrews, 67, out New Hampshirelived with the animal organ for nine months before later receiving a human donation.
Writing in the prestigious journal Lancet, scientists say this suggests the procedure could one day work as a ‘bridge’ between treatments.
Mr Andrews sought the unusual operation, called xenotransplantation, after spending two years with kidney failure caused by his cancer diabetes.
This left him spending three days a week on dialysis, a procedure that filters toxins from the bloodstream while the kidneys cannot.
He spent much of his time in a chair while the dialysis machine worked on his kidneys, with fatigue and muscle wasting robbing his ability to walk.
After six months of treatment he had a heart attack.
“I knew I was going to die,” he previously told the Daily Mail. “I thought there had to be another way.”
Tim Andrews (pictured above), a 67-year-old from New Hampshire, is the first person to receive both a pig and a human kidney transplant
During his search, Mr. Andrews came across the story of Richard Slayman, a 62-year-old from Weymouth, Massachusetts, who had received a transplanted genetically modified pig kidney in 2024 to treat his end-stage renal disease. Massachusetts Boston General Hospital.
Although initially successful, Mr. Slayman died just two months after the procedure after an unexpected heart problem. Doctors said at the time that there was “no indication” that his death was the result of the transplant.
“The more I read about it, the more I thought it could work,” Mr Andrews said.
At the time, the procedure had only been performed a few times in the US, but the team at Massachusetts General Hospital agreed to consider Mr Andrews if he completed several months of physiotherapy to strengthen himself and reduce the risk of his body quickly rejecting the animal organ.
In January 2025, he underwent the three-hour procedure that removed his diseased kidneys and gave him one pig kidney.
Mr Andrews spent a week in hospital before being discharged on 51 different medications to prevent his body from rejecting the kidney, which he named Wilma.
The organ came from a miniature pig from the Yucatan and was modified to be compatible with the human body.
‘It was great at first, which I realized was the steroids. They made you feel good, like I’m Superman. When they phased that out, it got a little bit harder. Bumps in the road.’
The kidney kept Andrews off dialysis, but over the next few months his condition gradually deteriorated.
He started urinating less and had flu-like symptoms such as fever, headache and nausea – signs of organ failure.
Finally, after 271 days, a world record, Andrews had the kidney removed in October 2025.
“For 271 days we fought it and fought it,” he said.
“I knew she was done probably a week before they were going to take it out. She was done fighting.”
The results of his story were published today by a team at Massachusetts General Hospital in The Lancet.
Authors of the study caution that this is an individual story and does not prove that the treatment could work for everyone.
However, they acknowledge that the results suggest that pig kidney transplants could one day help patients who have to wait a long time for a human donation.
With no more kidneys, Andrews was forced back into the dialysis chair and became one of 90,000 Americans waiting for a human kidney donation.
In Great Britain, more than 7,200 people, including 138 children, are waiting for a visa.
Despite the question, Only 3,000 kidney transplants are carried out in Britain each year.
“I thought, here I am again,” Andrews said. ‘I can’t walk, I want to sleep all day, I’m sick all the time. [Dialysis] is hard on the body, hard on the mind.’
At that moment he was convinced that he had only a few months left to live.
Many people on dialysis who do not have kidneys can live for several years, but if they are in the later stages of kidney disease, that time can be reduced to months.
The kidneys are essential for filtering toxins from the body and filtering minerals. Without kidneys, waste products and potassium build up in the bloodstream, damaging the lungs and heart.
Mr. Andrews, a father of two daughters, began to make peace with the inevitable when he got the call just before midnight on January 12, 2026, almost a year after his first experimental surgery: a human kidney was waiting for him, a near-perfect match, 80 miles away in Boston.
The photo shows the genetically modified pig kidney that was transplanted into Mr Andrews. He lived with it for 271 days
Pictured above are the surgeons at Massachusetts General Hospital performing Mr. Andrews perform
Medics at the hospital implanted the kidney on Wednesday morning, and by Friday afternoon Mr Andrews was on his way home to recover.
Xenotransplantation was first attempted in the early 20th century by attempting to insert pieces of a rabbit’s kidney into a child, which failed.
It wasn’t until the 1960s that a chimpanzee kidney was successfully implanted into an adult, who lived with the organ for nine months.
In the 1990s, researchers identified pigs as the ideal choice for these transplants because they are widely available and structurally similar to humans, although older attempts have used primates.
This procedure has been attempted about a dozen times since the early 20th century.
Mr. Slayman received the first successful genetically modified pig kidney in 2024.
A month after the life-saving operation, while recovering at home in New Hampshire, Mr Andrews told the Daily Mail “there are still bumps” in the road.
He now has a list of 20 anti-rejection medications, up from 51 last year, and must keep an eye on blood sugar spikes because immunosuppressive drugs can increase the risk of insulin resistance.
“But I’m going to feel good,” he said.
Mr Andrews is pictured above after the xenotransplant surgery. He had the organ for 271 days before it had to be removed because his body was rejecting it
Mr Andrews, pictured above center with his doctors, has encouraged others to become organ donors
Mr Andrews’ new kidney came from an unknown deceased donor. After his operation he has… posted on Facebook for the donor’s family. “I am so sorry for your loss,” he said in the message.
‘I grieve with you. It must tear you up, but I’m here to tell you that donating a kidney saved my life, and you gave hope to millions. Your family member is a hero. He is a hero, not just for me, but for the whole world.
“I will never be able to repay you, but I promise it will be in my heart. And it will be cared for and loved as long as I live, and I will basically preach all my life, and I’m not a preacher, about what this love has done.”
Mr Andrews said he was most looking forward to “living longer than I thought I would”.
He also knows that he is one of the lucky minority to receive a life-saving donation and that more organ donors are urgently needed.
“People should be donors,” he said.
‘There is no reason not to have ‘donor’ on your driver’s license. I’ve been doing that since I was sixteen. I didn’t know then that I would become a recipient; I thought I would definitely become a donor, but it turned out differently.
‘It’s a great feeling when someone saves your life. It’s hard because mine had passed away, so there’s a lot of emotion involved when someone has to die for me to continue living. It’s tough, but I’m dealing with it.’
However, he also hopes that more people in need of organs can benefit from xenotransplantation as a bridge to further treatment.
Mr Andrews said: ‘In a few years’ time we could see this becoming much more common and more and more people getting the organs they need.’
