A pig kidney that was changed using genetic technology worked inside a man in the United States for 271 days. This is the longest time an animal kidney has worked in a human, and it gives new hope for people who need organ transplants. The patient, Tim Andrews, got the pig kidney at Massachusetts General Hospital in January 2025 after getting very sick from kidney disease caused by type 2 diabetes.

Doctors decided to try a pig kidney because there are not enough human kidneys for transplant. In the United States, about 100,000 people wait for a kidney, but only 25,000 transplants happen each year. Scientists changed the pig’s genes so that the kidney would not be attacked by the human body, which helped it work for many months in Andrews.

After some time, the pig kidney stopped working well and was removed after 271 days. Andrews went back to dialysis, which is a process that cleans the blood, until he got a human kidney in January 2026. Doctors say his new human kidney is now working well.