Scientists have long thought about the idea of replacing a diseased organ with a healthy one from a donor. The problem at first was that the human body is not particularly receptive to foreign tissue. The immune system is like an army, constantly on guard against any invasion of bacteria, viruses or other potentially dangerous substances. When tissue from a donor is placed inside the body, this immune army sees it as a foreign invader and goes into battle mode. White blood cells attack and destroy the unknown tissue in a process known as rejection.
Eventually, scientists realized that the problem of rejection didn't occur when the organ donor and recipient were identical twins. The genetic similarity appeared to prevent the immune response. Massachusetts surgeon Joseph E. Murray used this concept to his advantage in 1954, when he accomplished the first successful kidney transplant between identical twins at Brigham and Women's Hospital in Boston.
Dr. Murray's surgery was a major breakthrough, but it wasn't a solution. After all, very few people have an identical twin they can rely on for organ donation. In the late 1960s, doctors figured out a way to perform transplants between nonrelatives by suppressing the recipient's immune response with drugs like cyclosporine. The trouble was that the drugs themselves were highly toxic. Between the risks of infection and those of the immunosuppressant drugs, most transplant patients didn't live long after their operation.
By the 1980s, anti-rejection drugs had improved to the point where transplantation surgery became pretty routine and far less risky than it had been a few decades earlier. Survival rates rose. Once surgeons had streamlined the process of transplanting essential organs -- heart, kidneys, liver and lungs -- they turned their focus to "nonessential" parts of the body. In the late 1990s, surgeons in Lyon, France, and New Zealand performed the first successful hand transplants. The next step was to attempt a face transplant.