It is much better for the donor - they are in hospital for only one or two days and they have much less post-operative pain

Robert Johnson, Manchester Royal Infirmary

And donor patients can usually go home after one or two days, rather than five days with standard surgery.

The study, carried out by scientists at the University of Maryland Medical Center, in the US, shows that the number of people willing to donate a kidney more than doubled since it introduced keyhole, or laparoscopic, surgery.

The centre has performed 460 laparoscopic kidney removals since 1996 - more than any other centre in the world.

It also runs an education programme to ensure patients know what is involved in both forms of surgery.

Using the laparoscope, surgeons only need to make a small incision near the navel, about two-and-a-half inches wide, as well as four small holes in which they insert instruments.

Traditional surgery

The traditional, "open" surgery requires an incision about ten inches long, which cuts through abdominal muscles, and the removal of a rib is required.

Donors stay in the hospital for about five days and need about six weeks to recover with open surgery. In contrast, the new technique allows a kidney donor to leave the hospital within two days and return to work or normal activities with two weeks.

Before the centre introduced keyhole surgery removals, 12% of patients went on to have a live donor transplant. Now the figure is 25%.

More people prepared to donate organs with new surgery

Dr Stephen Bartlett, director of transplant surgery in Maryland, presented the results of the study to the American Surgical Association.

He said: "The educational programme and the less-invasive method of donating a kidney have more than doubled the chance that a patient with kidney failure today will receive a transplant from a friend or loved one, compared to just a few years ago."

The US and the UK have long waiting lists for kidney donations which are needed by patients with renal failure who rely on dialysis machines to stay alive until they are given a new kidney.

At the end of 1997, there were 4.6m registered organ donors in the UK - but doctors said this was only around half the number needed.

Mr Robert Johnson, past president of the British Transplantation Society and director of the transplant programme in Manchester, said only a few specialist centres use keyhole surgery for kidney removals in the UK.

He added: "It is much better for the donor - they are in hospital for only one or two days and they have much less post-operative pain."