Nervy approach to fighting fat

The technique they are using is called vagal nerve blocking, which has been developed by St. Paul, Minn.-based EnteroMedics. A surgeon implants a matchbox-sized device in the patient's side that sends a high-frequency electrical signal to the vagus nerve. The electrical signal effectively blocks the nerve, causing the same effect on appetite and digestion as a vagotomy, says Mark Knudson, the company's chief executive. Turning off the signal restores vagus function, he adds.

This procedure is now being evaluated in a 300-patient placebo-controlled study underway at several U.S. research centers. Patients in both arms of the EnteroMedics-sponsored trial are implanted with the device. But it is not turned on in the placebo group.

"Vagal nerve blocking gets to the root of the problem to inhibit the hunger pains these patients have," says Dr. Ninh Nguyen, a gastrointestinal surgeon who is leading the trial at the UC Irvine Medical Center.

One of Nguyen's subjects, San Juan Capistrano resident Jeff Collins, 25, says he has lost about 20 pounds since he joined the trial in December at more than 300 pounds. Wearing the VBLOC device causes only mild discomfort, he says. And judging by the result, he thinks he is getting the therapy, not the placebo.

"I still love food, and still get hungry," he says. "But I am eating healthier, and eating a lot less than I used to."

Each has its downside

Both vagotomy and vagal nerve blocking have advantages and drawbacks. "With vagotomy, they snip something, and your anatomy is permanently altered," Knudson says. "With our method, you are living a more normal life."

"With the EnteroMedics approach, you carry a foreign object in your body that needs constant attention and could cause infection," Lustig says. "Vagotomy doesn't have those problems."

Both treatments are done using a technique called laparoscopic surgery, which is much less invasive than most weight loss surgeries. Knudson estimates that VBLOC therapy will cost about as much as gastric bypass surgery (about $25,000, according to the National Institutes of Health). Vagotomy as it is done now would cost about $9,000, Lustig estimates. But costs could come down if an experimental technique for snipping the vagus nerve using sound waves, developed by EndoVx, turns vagotomy into a simple outpatient procedure. This has been tested on animals and will be tried on human patients next year, says William Aldrich, the company's chief executive.