Could Nerve-Snipping Spur Weight Loss?
Monday, July 2, 2007; 7:23 PM
WASHINGTON -- An old ulcer operation is getting new attention as a possible alternative obesity surgery: a quick snip of a nerve that helps control hunger.
It's far from clear if cutting the vagus nerve really helps _ initial pilot studies in a few dozen patients have just begun. Skeptics abound, and even proponents say it wouldn't lead to nearly as much weight loss as more traumatic operations that shrink the stomach and reroute intestines.
It's part of a hunt for middle-ground options for people scared of today's surgery, or those not quite fat enough to qualify for it.
"By no means do I think this is a panacea," cautions Dr. Robert Lustig of the University of California, San Francisco, who is studying the method along with University of Rochester surgeons.
"But I think this will be a rational alternative for a cadre of patients that are sort of in the middle there. With as much obesity as we have in this country, that's a big middle."
More than 177,000 people underwent obesity surgery last year, according to the American Society for Metabolic and Bariatric Surgery. The most popular method is gastric bypass, stapling the stomach to create a tiny pouch. Options include placing an adjustable band around the stomach, or cutting off the stomach's side and rerouting the intestines.
Surgery can produce life-altering weight loss, if recipients adhere to diet and exercise advice, but each method comes with varying degrees of pain and risk, including a rare chance of death. So doctors are searching for alternatives.
Enter the vagus nerve, which snakes from the brain to the abdomen, with fibers reaching into multiple organs with different effects. Among them: The nerve spurs gastric acid production, and in the 1970s, surgery to cut where it attaches to the front and back of the stomach brought ulcer sufferers great relief _ after they recovered from open-abdominal surgery. Once better acid-reducing medications came along, this arduous operation was abandoned.
Yet surgeons at the time noticed, and subsequent animal studies confirmed, that these vagotomies could trigger weight loss. In addition to a less acidic stomach's slower digestion, the vagus helps control appetite-stimulating brain hormones and signals our bodies to store more fat, Lustig explains.
Since doctors today can snip the nerve far less invasively, through just five pencil-sized cuts in the abdomen, it was time to test in the obese.
Thirty patients had a vagus snip at UCSF or the University of Rochester. The study isn't complete. But of the 11 who are a year past surgery, all but one are shedding pounds, losing an average of 18 percent of excess weight so far, Lustig and Rochester's Dr. Thad Boss reported at last month's bariatric society meeting.
They suffered no serious side effects, and went home hours later with little pain.