HEALTH / Second Opinion

SOME science-fiction dreams become fact. Others remain unrealised. Man-made artificial substitutes for our internal organs have been one disappointment. The first effective artificial kidney was developed in the Netherlands during the Second World War by Willem Kolff, and its successors have kept thousands of victims of kidney failure alive; but almost all are waiting for a kidney transplant, to restore normal energy and quality of life. Despite vast research efforts, no one has yet developed an artificial heart, lung or liver that functions reliably for long periods.

The need for replacement organs is unarguable. In 1993, the United Kingdom Transplant Support Service Authority showed that 1,683 kidney transplants were done in Britain and the Republic of Ireland, well down on the 1,837 in 1989 and 1,873 in 1990. The waiting list for kidney transplants is now at an all-time high of 4,792. In 1993 there were 550 liver transplants, the most ever, and 310 heart transplants, a small decline from the peak of 340 in 1992. Lung transplants totalled 95. Waiting lists for these operations on the heart, lungs and liver have not risen in the same way as for kidneys because there are no artificial replacements to keep people alive while they are waiting for a transplant.

Government plans for a computerised donor-registration system will not deal with the growing gap between demand and supply. Donor organs come mostly from victims of accidents, and accidents are becoming fewer. In 1993, road accidents killed 4,000 people, many unsuitable as donors because of age or multiple injuries. Deaths from natural causes in relatively young people add a few more potential donors. By no means all come to the transplant surgeons: some of the decline in kidney transplants is said to be the result of pressure on beds in intensive-care units, making doctors reluctant to keep patients connected to life-support systems while arrangements are made to obtain consent from relatives, to certify brain death and to prepare for the removal of organs.

In some countries, such as the United States, much more use is made of donation of organs by living relatives. Most donations are of kidneys, but a parent can also give a child part of his or her liver, enough to save the child's life. Living donation may give excellent results, but critics of the practice quote examples of families put under great stress as tests are done to find the most suitable donor, with pressure then being put on someone to submit to major surgery. If - as sometimes happens - the donated organ is rejected, the unwilling donor is left feeling angry and exploited.

The long-term solution, gruesome though it may sound, seems likely to be the use of animal organs. One of the world's leading transplant surgeons, the American Thomas Starzl, is continuing research using baboons as a source of liver transplants for his patients. In the past 12 months, two patients have been given baboon livers. In neither case did the organ function effectively, but Starzl believes the problems of rejection are within sight of being solved - and he has a good track record as an innovator. Other research teams are trying to make genetic changes in pigs, to make their organs less likely to provoke strong immune reactions.