In a six-month open label trial the 31 obese participants who received the vagal nerve blocking device lost an average of nearly 15 percent of their excess weight. A quarter lost more than 25 percent, and three patients lost more than 30 percent. To see how much weight loss could be attributed to the device alone, patients were not put on any restricted diets or given counseling.
The goal is to find a less drastic alternative to bariatric surgery that will still yield significant weight loss. Bariatric surgery techniques include "banding" - placement of a band around the top part of the stomach to reduce its capacity - or bypass procedures which reroute food and remove part of the stomach.
According to the scientists, the mechanism is similar to that of a heart pacemaker, but instead of stimulating a normal, regular heartbeat, it uses high-frequency electricity to block the nerve impulses between the brain and the stomach and pancreas. A pacemaker continuously monitors the heart and regulates its beating. But here the patient flips a switch to activate the device so that the blocking signal can influence how the stomach functions and food is digested following a meal.
The lead wires are implanted in the abdomen laparoscopically, with electrodes attached to the vagal nerves and the neuroregulator, a pacemaker-sized device, is implanted just under the skin. While gastric bypass involves removing portions of the digestive tract and rerouting the flow of food and, therefore, is not reversible, the new system can be removed if desired and previous studies in animals have indicated that it does not damage or permanently affect the vagal nerves.
The researchers emphasise that the already started follow-up double blinded study will be important for gauging the device's true effectiveness. In an open label study there is always potential for the device to 'work' because patients believe it will.
MEDICA.de; Source: Mayo Clinic