New weight loss device appears effective

Tufts researchers have discovered that a pacemaker designed for the stomach could help obese people lose weight. Dr. Scott Shikora, head of bariatric surgery at Tufts New England Medical Center, presented the device to the American Association for the Study of Obesity last month.

Obesity surgery is a growing field in the US, where almost two thirds of the population is overweight and 30.5 percent is obese. The device, called the Internal Gastric Stimulator (IGS) is a possible alternative to gastric bypass surgery -- also known as stomach stapling. Stapling is an invasive surgical procedure requiring substantial modification of the gastro-intestinal tract. Essentially, the size of the stomach is reduced so that the patient consumes less food.

The gastricpacer represents a less invasive surgery and can be implanted laproscopically.

"What I think is that this will be another option of treatment for the obese," Shikora said. "[IGS may be] better or more appropriate-different treatments for different people."

The IGS is based on a device developed by an Italian surgeon, Dr. Valerio Cigaina, consisting of an electric pulse generator and two wires. The pulse generator is battery-operated and must be replaced every two to five years. The two wires are affixed to the stomach and send pulses which leave the person feeling full. After the device is implanted, a computer is used to control the generator to adjust it to a comfortable level for the patient.

"They don't feel a buzzing or a pain, they just don't have an appetite, or they get full very quickly. Some say, 'I don't know what it is. I just eat different now,'" Shikora said in an interview with the Associated Press.

Shikora indicated about 450 patients worldwide have been studied, including patients from the United States. The surgery is available commercially in Europe, and could be available in the United States soon.

"[The IGS] was tested in Europe at the time it was tested here, [but Europe's] version of the regulatory office seems to be less stringent than our FDA," Shikora said.

Shikora and his staff will conduct more tests, what he calls "pivotal trials", this winter. If successful the team may request FDA approval next year. "I suspect it could be available in two years," Shikora said.

The development of the IGS was initiated by a New Jersey-based company called Transneuronix. Their newest research project is "the pivotal study that, if successful, would lead us to the approval of the device through the FDA," Transneuronix employee Steve Adler said. Expected to last two to three years, the study will be conducted on 150 people throughout the US in six different hospitals.

The system has been tested in 30 people who were defined as obese in the United States. About two-thirds of the people tested lost weight-some dramatically.

One woman lost 108 pounds and became underweight. Successful surgeries results in an average loss of 18 percent of their excess weight. The other third of those in the study lost nothing.

The developers are still unsure how the device reduces appetite: potential explanations include hormonal changes, stimulation of stomach muscles, or variations on nerve activity. The placebo effect may also be an influence.

No deaths or serious complications have been reported in the patients studied, but the negative aspects of the IGS have not been fully tested. Certain objects and electronic devices with magnetic fields such as loudspeakers, and metal detectors may result in extra stimulation pulses from the IGS if placed within six inches of the implantation site.

Because this device is still in an experimental state, no estimate has been made about the cost of IGS.