FDA Approves Implanted Electronic Device For Treating Obesity

The FDA has approved an innovative "pacemaker" designed to treat obesity by "zapping" nerves that help the stomach communicate with the brain. The Enteromedics VBLOC Vagal Blocker Maestro System is the first surgically implanted device for treating obesity that the FDA has approved since the lap band gastric sleeve was given an OK in 2007.

How Does The VBLOC Maestro System Work?

The vagus nerve, also known as the pneumogastric nerve, is actually a pair of nerves that stretch from the medulla oblongata of the brain, along either side of the neck to the larynx (voice box), down to the stomach and heart, and on to the abdomen. It attaches to multiple muscles involved in speech, regulating heartbeat, perspiration, and peristalsis, the movement of digested food from the stomach and through the intestines. 

When the vagus nerve is cut, in a surgical procedure called vagotomy, now considered obsolete, the stomach releases less acid and digests food more slowly. Food stays in the stomach longer, and patients receiving the procedure eat less. On average, vagotomy patients lose 43% of their total weight in six months with diet and exercise. Vagotomy does not make the stomach smaller, but it keeps food in the stomach longer.

VBLOC is designed to avoid the excesses of the older surgical procedure. The "nerve zapper" can be implanted through minimally invasive surgery that takes about 45 to 90 minutes. The procedure does not require general anesthesia. Only the leads of the "zapper" are actually touch the stomach itself, just below the point it joins the esophagus. Most of the device is implanted just below the skin. The majority of patients can go home the same day.

The vagus nerve blocking device can be dialed up or down through controls placed outside the body. When eating more is desirable, it can even be turned off. People who receive the device don't want to eat as much, but they can eat normally when necessary.

Who Is A Candidate For The New "Appetite Zapper"?

VBLOC is not intended to be a first-line treatment for obesity. Suitable candidates for the procedure:

• Need to have tried and failed at least one medically supervised weight loss program in the last 5 years.
• Suffer from "morbid" obesity (a BMI greater than 40) or obesity with a BMI of 35 or more with hypertension, high cholesterol, or diabetes.
• Do not have a history of clotting disorders or other conditions that may make any kind of surgery dangerous.

See Also: The Stigma Of Obesity: Does It Make Losing Weight Harder Or Easier?

The new device would not be used with gastric bypass or gastric sleeve surgery. It also is not suitable for people who have a history of vasovagal syncope, loss of consciousness when the vagus nerve is stimulated so strongly that the heart reduces its output. For people who are medically eligible for VBLOC, however, it promises relatively easy weight loss without destruction of the stomach or other alterations to the anatomy of the digestive tract. Side effects, however, are not unknown.

What Can Go Wrong with Vagal Nerve Blockers for Weight Loss?

While the VBLOC Maestro System may work for some people, it is definitely not for everyone who needs to lose weight. The main reason to be cautious with this device or any other procedure involving the vagus nerve is that this nerve does more than just to control how fast food passes through the stomach.

The vagus nerve is involved in:

• The expansion of the stomach to receive more food. At your first meal of the day, it is possible to eat so much that you get indigestion.
• Stomach contractions that break the food into smaller particles. If your stomach is partially paralyzed, large chunks of food may pass into the bowel and cause constipation and/or inflammation.
• Release of gastric acid to digest food. Along with the release of gastric acid, the stomach produces intrinsic factor, which releases vitamin B12 from food. Low stomach acid can also result in incomplete release of minerals and vitamins from food, and, ironically, encourage the growth of bacteria involved in peptic ulcer disease.
• Emptying of stomach contents into the small intestine. Failure to pass food into the lower digestive tract, or gastroparesis, can result in significant stomach pain.
• Secretion of pancreatic enzymes that allow the digestion and absorption of dietary fat. When fat remains in digested food, the result is especially foul-smelling fecal matter than floats in the toilet bowl, resisting flushing. Lack of pancreatic enzymes can also interfere with absorption of fat-soluble vitamins A, D, E, and K, as well as beta-carotene, lycopene, and lutein.
• Sensations of fullness and satisfaction. Your stomach will feel fuller longer after installation of the VBLOC, but it may not release as much cholecystikinin, the hormone that tells your brain that you have actually been comforted by eating of comfort food.

Another important consideration in deciding whether to have the Maestro system implanted is the stability of the device. VBLOC is not the first vagal nerve blocker used to encourage weight loss. Older devices have sometimes had a tendency to migrate underneath the skin. In at least one case, a vagal nerve blocker migrated from the abdomen to the buttocks and had to be removed in emergency surgery.

The clinical trials of the device resulted, on average, of 10 percent weight loss. Some who weighs a whopping 440 pounds (200 kilos), for example, might reasonably expect to lose 44 pounds (20 kilos) in the first year the device has been implanted. Weight loss from vagal nerve blocking devices is much less than weight loss from gastric sleeve, gastric bypass, and old-style vagotomy, and there have been no long-term studies to determine how long weight loss is maintained.

See Also: Can You Be Healthy And Obese?

All of this is not to say that the VBLOC Maestro cannot work for you. Working with a doctor who has long-term experience in following up weight loss surgery, you may succeed in losing weight with Maestro when you have failed with diets and other medical interventions. Do not expect, however, for the vagus nerve blocker to do all the work for you. Maestro may make it easier to follow a diet, but it will not make it unnecessary to follow a diet.