Dilusional sister
People wanting to lose weight may be in for a shock. Literally!
A new type of pacemaker that sends mild electrical pulses to the stomach is being tested to see whether it can help people control their appetites and lose weight.
Background
Researchers at the University of Pennsylvania and eight other medical centers plan to implant the device in about 200 volunteers in a two-year trial.
Transneuronix Inc. of Mount Arlington, N.J., which has developed the gastric pacemaker, hopes the results from the trial will lead to marketing approval from the Food and Drug Administration.
"It is an exciting new development in the surgical field and less invasive," said Gary Foster, the clinical director of Penn's Weight and Eating Disorders Program and the principal investigator for the study's Philadelphia site.
Currently, weight-loss surgery involves shrinking the size of the stomach to limit the amount of food that can be eaten. It is considered the only effective way for morbidly obese people to lose weight, long term; about 141,000 people are expected to have the surgery this year.
But these surgical procedures have risks, infection, blood clots, ulcers and even death. They are also costly, approximately $25,000.
Scott Shikora, chief of bariatric surgery at Tufts-New England Medical Center who has studied the device for a number of years, said he doesn't believe it will replace the current surgical weight-loss techniques. Because it appears to have a good safety profile, it may be well-suited for patients who aren't candidates for bariatric surgery.
How the Gastric Pacemaker Works
The experimental device - which is called an implantable gastric stimulator - is a small battery-operated electrical generator about the size of pocke****ch that is surgically implanted in the abdomen. 2 wires connect it to the stomach wall.
In a similar way that a pacemaker sends electrical impulses to the heart, the experimental gastric pacemaker gives a small current to the stomach through 4 electrodes on the wires. The electrical current is activated, adjusted or monitored by a handheld computer in the doctor's office that communicates to the pacemaker through a radio signal. (Patients typically don't feel anything during gastric stimulation, according to the company.)
It is unclear how the electrical current works. It might cause the stomach to relax and signal a feeling of fullness. It could inhibit stomach hormones that normally increase appetite. Or it may send a satiety message to the brain.
Weight Loss Results so far
About 500 people have received the experimental gastric pacemaker in the United States and Europe since it was first developed in the mid-1990s.
Candy Bradshaw, a 47-year-old Worcester, Mass., corporate manager, had the device implanted in 1999 as part of an earlier study. She said she has lost about 100 pounds using it, going from a size 28 to a 14.
"You don't feel the device at all," said Bradshaw, who'd still like to lose an additional 30 or 40 pounds.
She said the gastric pacemaker makes her feel full more quickly when she eats, so she isn't tempted to go back for second or third helpings. And one bite too many, she said, will leave her feeling "Thanksgiving full."
The device has helped her take a hard look at her food choices and her lifestyle, Bradshaw said. She now power-walks five to seven miles a day and watches the amount of food she eats.
"You have to work with this device," she said. "It has helped me lose weight... . It is not a magic pill."
So far, study results have been mixed.
"After the implantation of more than 200 patients globally, it was found that some patients responded strongly and lost significant weight, while others seemed to have little or no response...," Shikora wrote this year in the journal Obesity Surgery.
In the journal, he said some patients didn't fare well in the early trials because the wires dislodged, people had abnormal eating behavior, or the current was too low. Transneuronix also discovered that some people seem to be predisposed to doing well with the device and has developed a screening procedure to weed out those who won't.
Weight Loss Implications for the future
"Researchers don't believe there is one cause of obesity," he said. ".... there is not going to be one treatment that will work for every patient. Our screen is very much focused on identifying patients *****spond to our therapy."
The device gained marketing approval last year in Europe, he said, but the company plans to delay its sales push until after the U.S. trial is complete next year.
For the trial, volunteers need to be evaluated for a range of medical and psychological issues.
Penn is looking to to enroll 20 to 30 people in the trial. They will receive the device during a one-hour surgery. But it won't be activated to begin with in all of them. The study will compare the weight loss between the group that has the device switched on with those that don't. After 1 year, both of the groups will be able to have the systems activated for 1 year.
All volunteers will take part in a weight-management program during the study period.
If the study results are positive, "this could be a landmark breakthrough." Shikora said.