Doctors the USA have transplanted a pig's heart a man. It is the first time this has happened. The doctors are the University Maryland Medical Center. They say David Bennett, 57, is doing well after his operation. Mr Bennett was very ill. The doctors said giving him the pig's heart was the only chance keeping him alive. Bennett spoke to doctors the day the operation. He said: "It was either die or do this transplant. I want to live. I know it's a shot the dark, but it's my last choice." The pig's heart came a genetically-modified pig. Scientists changed the genes the pig so its heart would be more suitable a transplant into a human.
The transplant operation took seven hours. Doctors received special permission U.S. authorities the experimental surgery. it, Mr Bennett would have died. Scientists have been researching pig-organ transplants years. They believe Mr Bennett's transplant means more transplants could take place the future. They said this could bring the world, "one step closer to solving the organ shortage crisis". Surgeon Dr Bartley Griffith said: "We are also optimistic that this first--the-world surgery will provide an important new option patients the future." Mr Bennett hopes his transplant will allow him to live longer. He said: "I look forward to getting of bed I recover."