In 1954, Vladimir Demikhov, a Soviet surgeon who had done important work to improve coronary bypass surgery, performed an experiment in which he grafted a dog's head and upper body including the front legs, onto another dog; the effort was focused on how to provide blood supply to the donor head and upper body and not on grafting the nervous systems. The dogs generally survived a few days; one survived 29 days. The grafted body parts were able to move and react to stimulus. The animals died due to transplant rejection.