Doctors believe they can cut the need for liver transplants by injecting sick patients with healthy cells instead.
Operations on babies at King's College, London, have so encouraged researchers that they are claiming two breakthroughs - the first cell transplants to treat liver disease in Britain and the first such transplant in the world to use only frozen cells.
The ability to freeze cells known as hepatocytes could mean the development of a "bank" that could stockpile cells for use as and when they are needed. The King's team sees no reason why the developments should not be adapted for adults too.
Four babies, suffering three different conditions, have so far undergone the injection treatment at ages ranging from two days to three years. One was effectively kept alive until he was big enough for an organ transplant and a suitable match could be found while the hope is that the others' livers will regenerate in a way that means that further major surgery is unnecessary.
Another boy came from a family who had already lost one child because of a missing blood clotting factor normally produced by the liver, and had another son who needed a synthetic version of the substance known as factor 7 injected daily through a vein in the neck at the cost of £700 a time.
But doctors identified the lack of factor 7 in the third son before birth and gave him three injections of hepatocytes when he was six weeks old. This has so far reduced his need for synthetic factor 7 by 80% and doctors hope another injection will mean that soon the baby, now eight months, will not need it at all.
All four babies - three boys and a girl - will still need to take drugs for the rest of their lives to combat the threat of rejection, but the long-term hope is that cells can be treated before they are injected.
Fewer than 700 people undergo liver transplants in Britain each year, about 100 of them children. There may be up to 150 people waiting for a suitable match at any one time.
The King's team, whose first successful operation was on a six-week-old boy last September, say the technique will allow far better use of donated livers, either as whole organs from people who have just died or from live donors who donate part of their liver.
Donated livers have to be transplanted within 16 to 17 hours, but using cells culled from parts of the organs that are not used in transplants should make far better use of scarce resources. In addition, putting spare cells in liquid nitrogen should preserve them for when they are most needed, 60% survive such storage at King's.
The injections, through the umbilical cord for children just a few days old or direct into the liver, only take 30 to 45 minutes instead of the six to eight hours for whole transplants. The fourth child underwent the treatment less than a week ago.
Anil Dhawan, a specialist in children's liver disease who heads the research team, said that it was too early to comment on the success of the latest operation but added: "All three babies are doing very well and without the hepatocyte injections one of the children would certainly have died.
"If the technique does prove a long-term success then 20-40 children could avoid liver transplantation each year in Britain. This could free up more donor livers and therefore increase the overall number of people who could be offered liver replacement.
"The fact that we can freeze hepatocytes will also make a considerable difference to how many patients can be treated and how quickly."
