The first full-face transplant could be less than a year away, a leading surgeon predicted today after the most complete version of the operation yet was performed in the United States.

Professor Peter Butler, of the Royal Free Hospital in London, said that the successful replacement of 80 per cent of a woman’s face would pave the way for his team to attempt a complete transplant shortly.

“We hope to make an announcement about this in the next 12 months,” said Professor Butler, whose team has ethical clearance for a research programme involving four face transplants.

Professor Butler was speaking after a team at the Cleveland Clinic, led by Maria Siemionow, conducted the first face transplant in the US and the most comprehensive one yet attempted.

In the operation, 80 per cent of the woman’s face was replaced with another from a female cadaver. The patient’s name and age were not released, and the hospital said that her family wanted the reason for the transplant kept confidential. The hospital will hold a press conference later today.

The transplant is the fourth to be performed, after two in France and one in China. The first such took place in France in 2005, on Isabelle Dinoire, a 38-year-old woman who had been mauled by her dog. She received a new nose, chin and lips, and doctors have described her progress since as remarkable.

The other patients to benefit so far have been a Chinese farmer, who was disfigured after being attacked by a bear, and a European man who suffered from neurofibromatosis, a tumour-generating condition made famous by John Merrick, the “Elephant Man”.

Professor Butler said that the latest operation marked significant progress. “We congratulate Dr Siemionow and her Cleveland transplantation team and wish the brave patient well for the future,” he said.

“Our thoughts are also very much with the family of the donor who, we understand, has helped not only the facial transplantation patient, but others, with various forms of organ donation.

“This courage and generosity in helping others not only live but have a good life, is one the greatest acts of human generosity.

“This latest operation once again shows how facial transplantation can help a particular group of the most severely facially injured people, for whom reconstructive surgery has not worked and those who are unable to live a normal life.

“These are people who would otherwise live a terrible twilight life, often shut away from public gaze.”

The operation would have been attempted only after extensive psychological assessment and counselling. It would have involved taking skin, blood vessels, nerves and facial muscles from the donor in a single sheet known as a “skin envelope”, and then using microsurgery to attach this to the recipient once scar tissue had been removed. The procedure would probably have taken eight to ten hours.

The face would have been taken from a brain-dead or very recently deceased donor who was similar in age, sex, skin tone and immune system type to the recipient. The patient will also have to take immunosuppressant drugs to prevent rejection.

Face transplants have prompted some ethical debate because they carry considerable risks for a condition that is not directly life-threatening. The foreign tissue can cause rejection and graft-versus-host disease, both of which are potentially fatal.

There are also concerns about the psychological impact of receiving a face from a dead person, both on the patient and his or her family.

Doctors who support face transplants counter that serious facial disfigurement is severely life-limiting, and often leads to depression and even suicide.

The Royal College of Surgeons gave ethical approval for face transplants in 2006, three years after a previous report deemed the procedure too risky. It has set a checklist of 15 ethical requirements. These cover the selection of patients, the technical skill of the surgical team, the provision of adequate and unbiased information to patients — including about how little is known about some of the risks — the provision of long-term psychological support and a properly constituted ethical approval team to vet all applications.

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