Dr. Daniel Davis, left, and Dr. Marc Bessler performed stomach surgery on Karleen Perez, using an experimental procedure that requires no cutting.

By DENISE GRADY

Karleen Perez lay unconscious on an operating table in New York City while her surgeons and two consultants from a medical device company peered at an overhead monitor that displayed images from inside her digestive tract.
The surgeons, Dr. Marc Bessler and Dr. Daniel Davis, had just stapled her stomach to form a thumb-sized tube that would hold only a small amount of food. The operation resembled others done for weight loss, with one huge difference. In this case, there was no cutting. The surgeons passed the stapler down Ms. Perez’s throat and stapled her stomach from the inside.
Inspecting their handiwork, Dr. Bessler said, “I don’t think you’ll get much better than that.”
The operation, meant to make people feel full after eating very little, is experimental. Only a few patients in the United States have undergone it, as part of a study paid for by Satiety Incorporated, which makes the staplers and hopes the government’s Food and Drug Administration will approve them.
Ms. Perez, a 25-year-old graduate student in social work, was the second patient at New York-Presbyterian Hospital/ Columbia to enter the study. Satiety employees advised her surgeons throughout the operation.
In Mexico and Europe , 98 patients have had the new weight-loss surgery, named Toga (for transoral gastroplasty). On average, those who have passed the oneyear mark after surgery have lost about 40 percent of their excess weight.
The procedure is part of a trend to make surgery less painful and invasive, to minimize risks and speed recovery. Many operations that once required big incisions are now performed through small slits, with cameras inserted to let surgeons see what they are doing on video screens.
Ms. Perez’s doctors took the next step: using a natural opening to avoid cutting through the abdominal wall. Dr. Bessler and other surgeons have used similar techniques to remove the appendix through the mouth .
There are older operations that produce more weight loss. In the United States, 200,000 people have them each year. Known as bariatric surgery, these procedures are often done through slits. But even the slits leave scars and slice through muscle, which causes pain. The operations can have complications, too, like hernias and leaks in the digestive tract.
Bariatric operations typically work far better than diet, exercise or drugs, and they often cure diabetes and reduce the risk of dying from heart disease or cancer. But only about 2 percent of those who might be helped by such surgery actually have it, Dr. Bessler said.
About 15 million Americans are morbidly obese, meaning their body mass index - a weight/height ratio - is at least 40 (overweight begins at 25). Medical guidelines recommend surgery when the index reaches 40 .
Ms. Perez is 175 centimeters tall and weighs 131 kilograms, for a body mass index of 42 - though her height and large frame help hide the weight. But she has mixed feelings about her appearance. “I don’t feel like it’s a big issue, but of course it is,” she said. “If I go out with my sorority sisters or friends to buy clothes, I probably can’t buy where they do. ”
More important, she said, is her health. She becomes winded too easily, and her blood pressure “is not great,” she said.
She hopes the operation will help her lose around 30 kilograms, maybe even in time for her graduation in spring from Stony Brook University in New York State.
The day after surgery, she was in good spirits despite a horrendous sore throat from the operation. She said she had awakened during the night wondering what she had done, and had thought, “This is going to be super life-changing.”
She would be on a liquid diet for several weeks. A nutritionist warned that eating too much or too fast could cause vomiting, and advised that the best time to lose weight would be in the next 6 to 12 months, because her body would try to fight the surgery by absorbing more nutrients.
Ms. Perez thought she could do it. She would start slowly, by taking longer and longer walks. She hoped to join a gym, start running, eventually finish a marathon. She wanted to look good for her graduation.
“My friends are going to be shocked,” she said. “Through struggle comes success.”