U.S. doctors have set a record: a pig kidney functioned in a patient’s body for 271 days.

A kidney from a genetically modified pig functioned for 271 days in the body of 66-year-old Tim Andrews, marking the longest period recorded to date for such a transplant. The procedure was performed on January 25, 2025, in the United States, for a patient with end-stage kidney failure caused by type 2 diabetes.

The organ began filtering blood immediately and spared Andrews from dialysis for several months. After about six months, the kidney’s blood vessels deteriorated, the organ became inflamed and was removed in October 2025. The patient underwent dialysis for 82 days, and in January 2026 received a human kidney, which is functioning well.

The kidney came from a Yucatan miniature pig whose genome had been modified at 69 points to reduce the risk of rejection, add elements of human “camouflage” and deactivate viruses in the animal’s DNA. The findings, published in The Lancet, suggest that xenotransplantation could be a temporary solution for patients waiting for a human organ. In the U.S., approximately 100,000 people are on the kidney transplant waiting list, while about 25,000 procedures are performed each yearس.