Liliana Gomez of Los Angeles has lost about 40 pounds since August. Last year, she was one of the first Americans to undergo scarless obesity surgery. ((Reed Saxon/Associated Press))

Doctors are testing a new kind of obesity surgery without any cuts through the abdomen, snaking a tube as thick as a garden hose down the throat to snap staples into the stomach.

The experimental, scar-free procedure creates a narrow passage that slows the food as it moves from the upper stomach into the lower stomach, helping patients feel full more quickly and eat less. 

Doctors say preliminary results from about 200 U.S. patients and 100 in Europe look promising.

After about 18 months, obese European patients have lost an average of about 45 per cent of their body weight, said Dr. Gregg Nishi, a surgeon at Cedars-Sinai Medical Center in Los Angeles. He discussed the European and U.S. studies during a Chicago conference this week for digestive disease specialists.

The procedure is only being done in the studies, which recently ended enrolment. Makers of the device used in the operation plan to seek federal approval if the research continues to go as planned.

While the two studies are still underway and only brief details are being released, Nishi said results are slightly better than typical results from conventional stomach stapling.

Risks include perforating the esophagus, as Nishi said happened to a patient at another centre, but otherwise, he said, there have been no major complications.

'When I found out it was going to be oral, through your mouth, I was like, "'Wow, that's kind of different.'" — Liliana Gomez

Some study patients have lost weight after unknowingly undergoing fake procedures — sedation and the tube, but no stapling. Results comparing them to the real thing aren't yet available.

Liliana Gomez, an administrative co-ordinator at Cedars-Sinai, was among the first Americans to have the scarless obesity surgery last year, as a test case for the U.S. study. She had planned on more invasive conventional surgery until learning that doctors at her hospital were studying the scarless stapling technique.

"When I found out it was going to be oral, through your mouth, I was like, 'Wow, that's kind of different,'" she said.

Since her operation in August, Gomez has lost about 40 pounds and dropped from Size 22 to Size 16.

Reduces infection risk, pain

The 35-year-old mother of three has a long way to go — she's still obese according to body mass index standards. But Gomez says she has cut her meal portions by more than half and still feels full, and is optimistic she'll continue to lose weight.

The new method is part of a medical movement to perform surgery through body openings such as the nose, mouth and vagina instead of making cuts. The idea is to reduce chances of infection and pain, and speed recovery. With no scars, there are cosmetic advantages, too.

Gomez had considered a gastric bypass operation, a more complex kind of stomach stapling, but worried about risks from that surgery. It reduces the stomach to the size of a golf ball and reroutes the digestive tract.

Whether done through one large abdominal incision or several tiny ones, gastric bypass is far more invasive and increases chances for malnutrition because it repositions how the stomach attaches to the intestines to restrict calorie absorption.

In 2007, 6,783 patients in Canada were waiting for bariatric surgery and 1, 313 procedures were performed. 

The average waiting time for bariatric surgery in Canada is five years, the longest of any surgically treated condition, according to a study published in the June issue of Canadian Journal of Surgery.

Another popular weight-loss surgery option involves putting an adjustable band around the top part of the stomach to create a small pouch.

No rerouting of digestive system

The experimental method Gomez had is the oral version of a different kind of stomach surgery, which reduces the size of the stomach with staples, but doesn't reroute the digestive system.

Surgery is generally considered a last-resort treatment for obesity, which affects more than 15 million Americans. Still, demand is high. More than 200,000 Americans are expected to have conventional forms of obesity surgery this year, according to the American Society for Metabolic & Bariatric Surgery.

Dr. Scott Shikora, the society's president, called the oral procedure exciting and innovative, but said, "It is too early for us to say this is going to be a breakthrough."

Shikora said many U.S. obesity surgeons prefer the rerouting surgery or flexible bands, and that it remains to be seen whether the oral method has the same drawbacks as more outmoded stapling procedures.

Satiety Inc., a California company that created the medical devices used in the technique, is paying for the research. Nishi said he has no financial ties to the company.

At Washington University School of Medicine in St. Louis, where the first U.S. procedure was done last summer, about 30 patients have undergone the treatment.

Side-effects have been minimal, including sore throats, nausea and some abdominal pain lasting less than a week, said Dr. J. Christopher Eagon. He said weight loss results from his centre aren't yet available.