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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.
The downside to vagotomy was that it reduced digestive activity so much that nutrient deficiencies could result. People who received a vagotomy sometimes developed pernicious anemia, a vitamin B12 deficiency that keeps the body from making red blood cells.
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.
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.