'It must be the way of the future, but is the time right?'

THE TRANSPLANT world has been waiting for the first operation involving a donated limb. The potential is immense - opening up the possibility of surgery to replace missing body parts damaged in accidents, by disease or simply by the wear and tear involved in ageing.

The surgery has been technically possible for several years. With advances in microsurgery, in which tiny arteries and nerves are joined under a microscope, dozens of patients have had their own hands reattached after being severed in accidents. But the use of a donated hand has been held up by problems of rejection. There are worries about the ethics of using powerful immunosuppressant drugs in patients who are not facing a life-threatening condition.

The skin stimulates a stronger immune response than other organs in the body and the Australian patient operated on in Lyons will have required large doses of drugs to prevent his body rejecting the transplanted hand. However, the drugs increase the risk of cancer and infection, because the immune system is suppressed, and there is also a risk of the reaction known as graft-versus-host disease, in which the transplanted hand rejects the body, triggering a potentially fatal reaction.

The International Federation of Societies of Surgery of the Hand decided at its meeting in Vancouver, Canada, earlier this year that a transplant of a donor hand should be carried out only in someone who had already had an organ transplant and was therefore already taking immunosuppressant drugs.

If the rejection problems could be overcome, the queue of patients for spare-part surgery could be huge. Although accident victims would be the obvious candidates, there is no technical reason why it should not be extended to degenerate or worn-out parts of the body. An elderly knee or hip joint could then be replaced with a youthful human joint with many years of wear left.

Simon Kay, consultant microsurgeon at St James's University Hospital, Leeds, who has reattached more than a dozen hands for people who have had them severed, said: "A replanted hand is an extremely useful hand. It is definitely worth doing. A transplanted hand is another matter. It has to be the way of the future, but the question is whether the time is right."

Mr Kay said that scientists at the Christine Kleinert Institute in Louisville, in the United States, had had a programme working towards the transplant of a hand for eight months. "There are big ethical and psychological issues. The drugs are toxic and the operation [to attach a donor hand] could not be described as life-saving."

Research was advanced into ways of overcoming the rejection problem without drugs. "It may be possible to remove the immune response in the transplanted part, or induce the body to recognise it as its own," Mr Kay said.