An Aug. 3 Health article about the experimental use of a gastric pacemaker to stimulate weight loss failed to fully identify George Washington University Hospital bariatric surgeon Fred Brody, who is scheduled to implant the device in a patient later this month. (Published 8/5/04)
When Jamie Finley begins an experimental weight management treatment later this month, she could receive a shock. Actually, the 41-year-old Woodbridge mother and business manager could get a whole series of them, and that's fine with her.
The shocks will come from a machine the size of a half dollar she's volunteered to have surgically implanted in her stomach as part of a clinical trial at the George Washington University Hospital Weight Management Program. Finley, a former Arkansan who grew up on Southern fried chicken and eggs cooked in bacon grease, hopes the novel device -- called an implantable gastric stimulation system -- will help her control her appetite and shed some of her roughly 200 pounds. And keep them off.
She's tried other means to reach that goal, improving her diet and trying reputable weight loss programs, but the extra pounds have always come back.
"This is a battle I've fought many times over," she said.
That makes her just the kind of patient researchers are seeking to try an approach less radical -- and therefore, with potentially broader application -- than gastric bypass.
Made by Transneuronix Inc. of Mount Arlington, N.J., the device consists of a battery-powered pulse generator and a 15-inch lead wire with two electrodes. At first glance, it resembles a stopwatch with a tail.
Like a heart pacemaker, the device sends out impulses that are generally undetectable to the patient, according to bariatric surgeon Scott Shikora of the Tufts-New England Medical Center in Boston, who has been testing the devices on obese patients for five years.
In this latest round of clinical trials, researchers will study whether the device fosters weight loss by causing an uncomfortable feeling of fullness -- satiety -- soon after a person begins eating.
In an earlier study of 30 obese patients receiving the pacemaker, 80 percent lost at least some weight in the first nine months after surgery, and 60 percent lost more than 10 percent of their body weight. Some patients lost more than 100 pounds, according to Shikora. But questions remain about how the pacemaker compares with other appetite-control methods in effectiveness and safety.
Over the next few months, GW researchers plan to begin testing the device on 30 more patients. Similar trials will take place at seven other medical facilities, including Tufts and the University of Pennsylvania.
About 500 patients worldwide have had the device implanted since the mid-1990s, including 150 in the United States, according to Transneuronix Executive Vice President Steve Adler. He's optimistic this latest series of clinical trials will lead to Food and Drug Administration approval of the device. The implant procedure has been available in Europe for about a year.
Bypassing a Bypass
In an operation that takes about an hour, the pulsor is slipped through a two-inch incision in the belly into a shallow pocket in the abdominal wall. The lead and electrodes are then attached to the stomach muscles with permanent stitches.
As with any surgical procedure, there are risks. Some of the gravest include perforation of the stomach, pulmonary embolism and complications linked to use of anesthesia. But Shikora, who's worked with the pacemakers more than any other U.S. doctor, said he has yet to witness any problems.
"It's been remarkably complication-free," he said.
In contrast, about 20 percent of gastric bypass patients experience such serious complications as surgical leaks, hernia, wound infection and bowel obstructions. About one in 200 gastric bypass patients dies as a direct result of the procedure.
A week or so after the pacemaker surgery, the device is activated remotely by computer. The battery is expected to last about five years before it needs replacement in follow-up surgery.
Arthur Frank, medical director of the GW weight loss program, said he doesn't expect the pacemaker to substitute for other weight loss methods. But it could be an alternative for people who haven't had success with traditional methods like diet and exercise or even weight loss medications. And it may be particularly useful for patients like Finley, who are not considered heavy enough to justify a gastric bypass.
"Is it interesting? Yes," said Frank. "Is it effective? That's what we're trying to study. What we do know is it's a good deal less invasive than gastric bypass. Is it safe? We'll be looking at that, too."
In addition, if the device does prove effective, researchers hope to get a better sense of how and why. For now, that's a puzzle, said Brody.
One theory holds that the pulsor helps relax the stomach muscles and thereby communicate a feeling of satiety to the brain. Electrostimulation of the stomach already is an accepted treatment for gastroparesis -- a serious digestive disorder that causes nausea and vomiting, Brody said.
For Finley, not just weight but also related health concerns are driving her latest push to slim down. Diabetes and high blood pressure -- both closely linked to obesity -- are rampant in her family.
"I'm afraid it's just a matter of time before the weight catches up with me," she said.
Already, excess weight eats away at her energy level.
"Around 2 p.m. every day I hit bottom," she said. "I have no energy left. And don't even talk to me about climbing stairs."
Being heavy also has been hard on her self-esteem.
"I know I'll feel better about myself if I can lose the weight," she said. Though reaching her weight goal would mean dropping about 60 pounds, Finley said she'd be happy losing 25.
That's how Candy Bradshaw, a 47-year old corporate manager in Boston, said she felt five years ago when she reluctantly agreed to join a friend in the pulsor's first round of clinical trials at Tufts.
"I figured: If it works, it works; if it doesn't, it doesn't," said Bradshaw.
Bradshaw has since shrunk from a size 28 to a size 14. (Meanwhile her friend, who didn't lose weight, dropped out of the trial long ago, opting instead for gastric bypass.) But even with the pacemaker, slimming down has been a struggle, Bradshaw said. Not until doctors adjusted the wires during a second surgery nearly two years later did she see any results.
Now, she said, she feels full after eating a small portion and can go for much longer periods without feeling hungry.
"I call it my Thanksgiving-full feeling," she said. "If I went to eat again, I'll get uncomfortable after a couple of bites."
But Bradshaw said the device doesn't deserve all the credit for her success. Since getting the implant, she's also started a rigorous exercise program that has her waking up at 4 a.m. each morning to complete a five- to seven-mile power walk before work. She's also become choosier about her diet and eating patterns -- an important part of weight management, many weight loss experts say.
"I consider [the device] an aid. It helps me stay on track. But if you just go from eating six doughnuts to four, it's not going to work and you're not going to lose the weight," she said.
Though she can't feel the current or any other sensation from the device, she knows it's there because she can feel its hard case when she presses below her rib. "I tell my son it's my battery pack," she said.
Researchers hope that at the end of the two-year trial, they'll have a better understanding of who are the best candidates for the device. They will be testing it on both men and women; all participants will have a body mass index -- a measure of weight in relation to height -- between 35 and 55 (30 qualifies as obese; gastric bypass patients generally must have a BMI of 40 or higher).
To rule out a placebo effect, the study will be double-blinded: For the first year, neither the researchers nor the patients will know which devices are activated, said Frank. During the second year, all the devices will be turned on.
All participants will receive nutritional counseling and be urged to follow a low-calorie diet and exercise program.
Finley said she hopes she'll be one of the patients chosen to receive a working device from the start, but either way, she's looking forward to getting started.
"I like the fact that they're not going to be pumping chemicals into my body," she said. "Under the worst-case scenario, I'm getting a year of one-on-one counseling with a weight loss professional. Either way, I win."
Rita Zeidner is a frequent contributor to the Health section.