Virginia Commonwealth University researchers are enrolling people in a study testing an implanted weight-loss device that curbs hunger and increases feelings of fullness so weight drops almost effortlessly.

The therapy consists of a thin, pacemakerlike disk placed under the skin and attached to thin, wire electrodes that are wrapped around nerves on the stomach. The nerves are vagus nerves, which branch off the brain and carry signals between the brain and several organs, including the stomach, small intestine and gall bladder.

"This is designed to block impulses from the brain that control sensations of hunger and fullness," said Dr. James W. Maher, lead investigator at the VCU Surgical Weight Loss Center.

"It alters the stomach's ability to handle large meals. It slows the emptying of the stomach and also cuts down secretions of some of the digestive enzymes that control absorption of fat," Maher said.

The study will enroll up to 225 patients at 15 sites in the United States and Australia. Maher, chairman of general surgery at VCU, said the first patient in the VCU arm of the study was enrolled yesterday.

The device being studied is made by EnteroMedics Inc., based in St. Paul, Minn. The treatment is called VBLOC therapy.

Maher said the therapy evolved from observations noticed about 25 years ago in patients being treated for peptic ulcers by having the vagus nerve cut, an operation called a vagotomy.

"If you cut the vagus nerve . . . they tended to lose some weight," Maher said. "With time, they would gain the weight back. It seemed like the body got used to effects of having the vagus nerve cut."

With the VBLOC system, vagal nerve impulses will be blocked for 12 hours a day so that the body does not get used to having the nerve blocked and compensate.

"The patient wears what they call an induction coil on a belt around them for 12 hours a day," Maher said. "That induction coil transmits the electrical energy from a battery to the pacemaker device. At the end of the day you take the induction coil off, charge it overnight and then put it back on the next morning."

To qualify for the study, patients must have a body mass index between 35 and 45. Those with a body mass index under 40 also must have sleep apnea, high cholesterol, obesity-related cardiomyopathy or high blood pressure. A 5-foot-6-inch person weighing 217 pounds would have a BMI of 35 and at 279 pounds would have a BMI of 45.

Maher said the therapy is less invasive than gastric bypass weight-loss surgery, which makes the stomach smaller and may be a little easier on patients than lap-band surgery, in which a band is placed around the stomach to partition off a segment.

"It's still a major procedure," he said of the VBLOC surgery.

Maher said there have not been any significant side effects. But because the vagus nerve also is attached to the brain, heart and other organs, the U.S. Food and Drug Administration has asked the researchers to look for specific side effects, including heart rhythm changes, Maher said.

Vagus nerve therapy is used to treat epilepsy and major depression. Houston-based Cyberonics, which makes a vagus nerve stimulator to treat epilepsy, has teamed up with Johnson & Johnson to develop an anti-obesity device.

For details on the VBLOC study, call (866) 978-2562.

Contact Tammie Smith at (804) 649-6572 or TLsmith@timesdispatch.com.