British women may be offered a “natural” form of breast enlargement that uses stem cells and fat from a woman's own body, under plans being considered by doctors.

The technique, pioneered in Japan, results in breasts that look and feel smoother than conventional cosmetic surgery using implants. This is because the stem cells enable the fat to grow its own blood supply, thus becoming an integral part of the breast rather than a foreign lump.

Stem cells have the potential to change into any cells in the body. They are found in most tissues, especially fat.

Dozens of women in Japan have received the breast enlargements during trials. Last week German medical authorities gave approval to the process. Under Brussels rules, this means that the procedure is now legal throughout the European Union, including Britain.

Doctors here said last week they found the technique “appealing”. The technique’s long-term effectiveness without side — effects still needs further tests, but doctors are already enthusiastic.

“I’m newly convinced,” said Venkat Ramakrishnan, a specialist in plastic and reconstructive surgery at Mid Essex Hospital Services NHS Trust. “A lot more people have to use it and prove it, but it does seem to have something to it.”

In addition to cosmetic breast enlargements, which 26,000 women in Britain underwent last year, the procedure can be used for rebuilding breasts after cancer surgery and to repair facial disfigurements.

In a further variation of the technique, a Spanish hospital last week treated a patient with fat-derived stem cells to repair a severely damaged heart.

Both types of treatment rely on a process developed by Cytori, a Californian firm, for extracting adipose tissue and concentrating its stem cells. It has mechanised the process so that procedures which used to take weeks can be done in hours.

Much stem cell research has been directed at finding therapies for diseases such as Parkinson’s, Alzheimer’s, motor neurone and muscular wasting.

The use of the cells for cosmetic breast surgery was begun in 2004 by Kotaro Yoshimura, a surgeon at Tokyo University medical school. He said last week: “I believe that within five years my procedure will be available as plastic surgery and that it will prove very popular.”

“Scientists and doctors are starting to believe that the best clues to curing and improving our bodies are inside our bodies in the form of stem cells,” said Cynthia Fox, author of Cell of Cells, a new book about the worldwide race to master stem cell technology.

“Breast augmentation is cosmetic but these cells have the potential to treat diseases ranging from cancer to Alzheimer’s.”

Yoshimura said last week he had had “no major problems” with the 39 women to whom he had so far administered the treatment. He has also used it to grow new tissue on the faces of three people with disfigurements.

He claims his technique has advantages over, for example, silicon and water implants which can leak. In addition, some 50% of implants that use plain fat — without the stem cells “boost” — die. This is usually caused by the fat losing blood supply when it is transplanted from the patient’s buttocks or thighs.

The process used by Yoshimura, Cytori and others involves extracting twice as much fat as is required for the implant. Half is treated to separate out the stem cells. These are then added back into the remaining fat to be injected into the breast in a series of treatments.

Some stem cells form more fat and others develop into a living blood supply for the new tissue which can grow into the surrounding breast.

The main drawback is that the stem cell implant gives only half the extra volume of new breast compared with conventional enhancements — 150 cubic cm per side compared with 300 cubic cm for implants. Another limitation is that thin patients may not have enough spare fat.

Eva Weiler-Mithoff, a consultant at Canniesburn hospital in Glasgow, said the technique offered particular benefits for patients needing reconstructive surgery after having mastectomies.

“The most distressing effect of radiotherapy is that the blood vessels shrivel up,” she said. “Stem cells can differentiate into new blood vessels, which could mean that more fat cells will survive.”