(CNN) -- The woman who received a partial face transplant earlier this week thanked her doctors when she awoke 24 hours after her surgery, a team of doctors said Friday.
"Her tracheotomy tube was removed, and, putting a finger over the tracheotomy canal, her first word was 'merci,'" said Dr. Bernard Devauchelle, one of the many surgeons who carried out the surgery on November 27 in Amiens, northern France.
During the operation, teams of doctors grafted a triangle of tissue including a nose, lips and chin onto the face of the 38-year-old divorced mother of two teenaged daughters, who had been attacked by a Labrador and whose name has not been disclosed. The dog was put down.
The donor tissue came from a woman who had been declared brain-dead, with the permission of that woman's family, doctors said.
The surgery is believed to be the first of its kind. While the technology to perform it has been available for some time, ethical concerns have delayed the implementation of such procedures. Watch doctors discussing the operation
But doctors in this case said they had no reservations about what they did.
"When I saw the patient, and I can tell you it was very... I never had any hesitation. When you saw her face, disfigured, missing most of her nose, lips and chin... with difficulty to speak and eat, at that point we doctors decided to improve the quality of life for this person," said Dr. Jean-Michel Dubernard, a leading transplant expert who also participated in the surgery.
Dubernard explained that traditional plastic surgery methods would not have been able to repair the damage to the woman's face, and that the wounds on it were worsening.
"When I first met her she could speak a bit but it was getting worse," he told reporters at a news conference in Lyon.
Devauchelle said most of the facial muscles of the recipient were preserved and it was mostly a question of attaching the donor skin and nerves.
The procedure went smoothly and four hours after surgery blood was circulating in the donor graft.
"The surprise was ... the (matching of) the skin color and texture were nearly perfect, it was better than we expected," Devauchelle said.
Dubernard, who has performed hand transplants in the past, said he believed the woman would consider the graft part of her own face when feeling is completely restored in that area.
He also explained that the woman's face "will not exactly resemble her face before, but neither will it completely resemble that of the donor."
"It will be a new face," Dubernard said.
The patient must still work on articulation, but she can speak a bit and has been able to eat strawberries and chocolate and drink coffee and fruit juice, doctors said.
The woman is undergoing a strict regimen of immunosuppression therapy so her body does not reject the donor skin, a problem that has been encountered in other skin transplants, the doctors said.
She is also being monitored and aided by a team of psychologists, they explained.
Consultant facial surgeon Iain Hutchison at St. Bartholomew's hospital in London, said while all medical advances were to be celebrated, the operation created many issues. (Watch the future of these transplants -- 1:37 )
"This was a quality-of-life operation rather than a life-saving operation and has many implications for the recipient and donor's families," he told the UK's Press Association.
Hutchison is chief executive of Saving Faces, a UK charity for facial surgery research.
"The recipient chose to take the risk of the operation failing if the blood vessels become blocked. There's a medium-term risk of the immunosuppressant drugs failing to control rejection of the donor tissue, and a long-term risk of the drugs causing cancers.
"She could be back to square one without a face, needing further reconstruction operations."
Peter Butler, consultant plastic surgeon at the Royal Free Hospital in Hampstead, north London, has led one of four teams worldwide that have been working towards carrying out the procedure.
Butler, who has been researching the psychological impact, hopes to carry out the procedure in the UK in two years and welcomed the news.
"It is a great step forward for European science and medicine," he told PA.
Brendan Eley, chief executive of the Healing Foundation, said: "Facial transplantation is a very exciting and fast-developing area of modern surgery, offering some hope to a small number of people who survive very serious disfiguring conditions.
"Though the surgical techniques to perform these operations are well established, the Healing Foundation would like to see further research, especially into the issues of immunosuppression and the psychological aspects, before advocating the procedure more widely."
Dr. Daniel Sokol, researcher in medical ethics at Imperial College, London, said the main ethical issue was one of informed consent.
"Did the patient give adequately informed consent to the procedure? Did she understand the risks and implications of the transplant?
"If the answer to these questions is 'yes,' and I see no obvious reason why it should be otherwise, then all those involved should be congratulated for their skill and courage."
Similar procedures have been discussed by American doctors, but because of ethical concerns they have not been approved.
In the United States, doctors at the Cleveland Clinic in Ohio are currently screening patients for a potential full face transplant, an official there said Wednesday.
It's the only U.S. institution that has the approval of its internal review board to do the procedure.
Such an operation would be conducted only on severely disfigured patients, the official said, most likely on burns victims, because those patients usually still have their bone structure and musculature in place.
The procedure should not be considered elective, the official said.