July 10, 2008 -- It's one version of the American dream: lose weight without changing your lifestyle and with little or no side effects. That's what a new weight loss device, called the VBLOC, promises.
The VBLOC, now entering the final stage of FDA testing, is basically a receiver. Patients wear a belt that transmits electronic impulses that block signals traveling between the brain and the stomach via the vagus nerve. The result is hunger pangs are quelled and the patient eats less.
The device has already helped a dozen patients lose on average 29.1 percent of their excess body weight. This summer a final clinical trial begins, testing the device's safety and effectiveness on 300 patients.
"With our device there is no restrictive diet, no change in lifestyle," said Greg Lea of EnteroMedics, which makes the device.
Altering the vagus nerve is not a new idea.
Decades ago, before they knew such conditions were caused by bacteria living in the stomach, doctors tried to treat ulcers and other stomach problems by cutting the vagus nerve. Other weight loss devices stimulated the vagus nerve, but failed commercially. This is the first device that electrically blocks the vagus nerve signals.
Every five minutes, 5,000 hertz worth of electricity flows out of the neuroregulator and down two laproscopically inserted electrical ledes onto the vagus nerve.
That much electricity causes a massive depolarization on the vagus nerve, making communication between the brain and the stomach impossible. A normal nerve takes about 200 hertz for an impulse to be transmitted.
Without those signals the stomach doesn't expand when a person eats, making them him fuller sooner. It also limits the release of digestive juices, extending digestion and keeping food in the stomach longer.
Other surgical procedures, such as gastric bypass and gastric banding, physically stop the stomach from expanding, by either surgically cutting out a section of the stomach and making it smaller, or by wrapping a band around the stomach that stops it from expanding during eating.
Gastric binding patients typically lose about 30 percent of excess body fat, and gastric bypass can achieve even more, although the procedure is more invasive.
All of the devices require surgery to be implanted, although EnteroMedics is working to insert the device through the esophogus, eliminating any external scars.
The problem with bypass and banding is that many patients have a difficult time eating fibrous vegetables and red meat after the procedures and often complain of nausea and vomiting.
Some nausea has been reported by patients on the Enteromedics device, but it doesn't appear to be as pronounced as with other surgical weight loss techniques.
For the trials, the device will only have one setting, but Lea says that it could be adjusted depending on the needs of the patients to lose more or less weight.
Doctors involved in the device's clinicial trials, including John Morton at Stanford University and Henry Buchwald at the University of Minnesota, think the device is "very promising."
"It's safe, simple, and can be reversed," said Buchwald. "If it passes its trials, and indications are that it will, it will take its place among other weight loss surgeries."
Other physicians not involved in the trials also expect it will work but downplay the overall significance of the device.
"This is a hopeful and useful thing," said Richard Atkinson, editor of the International Journal of Obesity. "But what I hope will happen is that this will enable us to better tailor treatments for patients who don't respond to a particular weight loss procedure."
While the success of the device remains to be seen, one thing is certain -- there will be plenty of people ready for a shrinking waistline.
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