An end to baldness - for those who can stomach it

But it works, and thousands are signing up for the treatment, known as the "Fleming-Mayer flap". Scores of Britons have already flown to America to have it, and patients are talking of having their lives transformed by thick, lustrous hairlines that make them look 10 or 15 years younger. It seems, in the parlance of the hair-restorer ads, "revolutionary".

The Fleming-Mayer flap - named after the two specialists who perfected the technique - involves partially removing a section of hair-bearing scalp from the side of the head, twisting it through 90 degrees and then reattaching the loose end to the top of the skull. As the blood supply is never cut off, the hair continues to grow as before - just in a more prominent position.

The operation, which takes a little over an hour, boasts a 100 per cent success rate, giving previously thinning patients a thick, natural-looking head of hair almost instantly.

One recent patient is Chris, a 42-year-old salesman who had the procedure in June and emerged talking, and looking, like a living advertisement for it.

"It's amazing - miraculous, even," he said. "My hairline started to recede in my early 30s, and I just started to look older and older."

Since the procedure, Chris said, he has been astounded by the results.

"It's when you meet people for the first time that you notice the difference, and really feel the confidence. It has taken 12 to 15 years off me, and the thing that's really incredible about this is that it's instantaneous: you literally come out of surgery and you have hair. They take the bandages off, you look in the mirror and you think: 'This can't be real.'"

Dr Richard Fleming, who performs between 12 and 40 procedures like this every month at his Beverly Hills Institute, told The Independent on Sunday that British men already account for a significant proportion of his clientele.

"I'd say we operate on British people every single week, or if not, very close," said Dr Fleming. "We have a lot of Brits flying over for this: actors, entertainers, public figures, industrialists - we get people from all over." Dr Fleming said the operation, which costs around £7,000, had been modified at the Beverly Hills Institute over the past two to three years. He estimated that between 50 and 75 British men had already had the procedure there.

"You talk to any bald man and give him the choice. Then see what he decides," Dr Fleming said. "A lot of people in professions where appearance is important, be they celebrities or businessmen, see this as an investment."

During the operation, the original patch of thinning scalp is removed and discarded before the banana-shaped flap is twisted into position and sewn into place. Surrounding skin is then stretched to cover the gap, as in a facelift.

"People like this procedure because you get immediacy and normal, uniform thickness," said Dr Fleming. "The bandages come off after three to four days and reveal a full head of hair that can be washed and styled straight away. Within three weeks, you'll be able to disguise everything we have done."

Greg Williams, a member of the British Association of Aesthetic Plastic Surgeons (BAAPS), one of the UK's leading experts in hair transplantation, said it would be some time before cosmetic surgery on this side of the Atlantic caught up with the US.

"In general we're lagging behind the cosmetic surgery available in the States," Mr Williams said. "But I think things like male hair transplantation will become much more common and available here over the next 10 years."

Meanwhile, Chris thinks his hairless peers should be aware of the procedure. "The thing I find most amazing is that most people don't know this is available," he said. "I see about 100 men a week through travelling with my job, and think: 'That person could have a full head of hair; they just don't know it.'"

HOW IT WORKS

* A banana-shaped piece of hair-bearing skin is marked out on the side of the head

* Incisions are made and the flap is loosened, always remaining attached to the head in order to maintain the blood supply

* The bald area is cut out of the patient's scalp and removed

* The flap is twisted, flipped over the top of the head and sewn into place where the bald patch was. Surrounding skin is stretched lower down to compensate