Washington, June 29, 2008 - A promising new implant to reduce obesity is likely to replace existing bariatric surgeries, which are painful and invasive, according to a study here.

In a six-month open trial involving three medical centres in Australia, Mexico and Norway, 31 obese participants who received the vagal nerve-blocking device, lost nearly 15 percent of their excess weight. A quarter shed more than 25 percent, and three patients lost more than 30 percent.

Michael Camilleri, a Mayo Clinic gastroenterologist, helped design the study and one whose previous work and know-how contributed to development of the device in collaboration with EnteroMedics.

Camilleri said the goal is to find a less drastic alternative to bariatric surgery that will still yield significant weight loss.

"For this study, we wanted to get an initial assessment of whether blocking the vagus nerve electrically could cause obese patients to feel full after a normal-sized meal," Camilleri explained.

"Patients were not put on any restricted diets or given counselling that typically accompanies gastric banding or bypass. We wanted to determine how much weight loss could be attributed to the device alone."

Camilleri says vagal nerve blocking device (VBLOC) therapy is similar to a pacemaker. 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 the patient flips a switch to activate the VBLOC device when the system is worn during the daytime hours 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 neuro-regulator, a pace maker-sized device, is implanted just under the skin.

Bariatric surgery includes "banding" - placement of a band around the top part of the stomach to reduce its capacity - or bypass procedures that reroute food and remove part of the stomach.

While gastric bypass involves removing portions of the digestive tract and rerouting the flow of food and, therefore, is not reversible, the VBLOC delivery system can be removed.

Besides, there is no distortion of digestive system anatomy as is the case with both gastric bypass and gastric banding, reports Eurekalert.

There have been no significant issues related to food intolerance, nausea or vomiting as is common with both bypass and banding.