How an Injection of Tiny Beads into Stomach Arteries Might Help with Weight Loss

The stomach can hold a bit more than a quart (1 liter) of food at once. (Image credit: Dreamstime)

An experimental obesity treatment that involves injecting tiny beads into the arteries of the stomach may help some people lose weight and keep it off for at least a year, according to a new study.

In the study, people who received the treatment, called "bariatric embolization," lost about 11 percent of their excess weight, or 17 lbs. (7.6 kilograms), on average, after one year.

However, the study was small, involving only 20 participants, and much more research is needed to confirm the procedure's safety and effectiveness, the authors said. [The Best Way to Lose Weight Safely]

Still, "this is a great step forward for this procedure," which has been under development for the past decade, study lead author Dr. Clifford Weiss, an associate professor of radiology at Johns Hopkins University School of Medicine in Baltimore, said in a statement.

The study was published today (April 2) in the journal Radiology.

Microscopic beads

For the procedure, doctors first use a thin tube called a catheter and thread it through an artery in the wrist or groin to the stomach. Then, they inject the microscopic beads into the catheter, which travel along the tube and partially block the arteries that supply blood to the stomach. This, in turn, is thought to suppress the production of hunger-stimulating hormones, thereby reducing appetite, the researchers said.

The procedure aims to change people's metabolism in a way that's similar to what's seen in people who undergo weight-loss surgery, also known as bariatric surgery. But bariatric embolization is less invasive than bariatric surgery, and it takes patients less time to recover, the researchers said.

In the study, the 20 participants were considered "severly obese," with an average weight of more than 300 lbs. (139 kg) and a body mass index (BMI) of 45. On average, participants were more than 150 lbs. overweight.

During the first month after the procedure, the participants lost, on average, about 8 percent of their excess weight (the amount of weight above their ideal weight) and reported a reduction in feelings of hunger. After the first month, their reports of hunger increased but were still less than they were before the procedure.

After 12 months, participants had lost, on average, 11.5 percent of their excess weight and reported improvements in their quality of life.

There were no serious complications tied to the procedure. Eight patients developed stomach ulcers that didn't cause any symptoms and healed after three months.

Obesity treatment?

Dr. David Cummings, an endocrinologist and professor of medicine at the University of Washington School of Medicine, said it's unclear whether the weight loss in the participants was due to the placebo effect — one that results from a person's belief that the treatment is working, rather than any physiological effect of the treatment.

"Anyone enrolled in a [weight loss] trial typically loses a little weight," regardless of whether they receive the real treatment or a placebo, said Cummings, who wasn't involved with the study. (The new study can't determine how much weight loss was due to the placebo effect because it didn't have a placebo group.)

Cummings noted that although the study participants lost about 11 percent of their excess weight, their overall weight loss was only around 5 percent, which is "right at the level you'd expect from the placebo effect."

This research needs to move to "a more definitive trial where they compare it against a placebo group," Cummings told Live Science.

Dr. Scott Cunneen, director of Bariatric Surgery at Cedars-Sinai Medical Center in Los Angeles, said the method seemed promising, "but you need a lot more people [in a study] before you'd really know that it's safe."

One potential safety concern is that the procedure reduces blood flow too much, which could lead to stomach perforation and leaking, Cunneen said, although this wasn't reported in the current study.

It's important to note that bariatric embolization doesn't lead to as much weight loss as does bariatric surgery, which is tied to weight losses of more than 30 percent.

But the weight loss seen in the study is "well within the range that people generally can achieve with [weight loss] medications," Cunneen said.

The researchers stress that bariatric embolization isn't meant to replace bariatric surgery. Instead, it could be used as a supplement to diet and lifestyle changes to help treat obesity, they said.

Cunneen agreed. "Less than 1 percent of the people that qualify for surgery to help them with their weight are [actually getting] surgery … they're looking for something that's less invasive and less severe," Cunneen told Live Science. "This could fill that category."

Cummings added that it would be interesting to see if the procedure does reduce levels of ghrelin, a hormone that stimulates appetite, and if so, how long the effect lasts. (Levels of ghrelin drop significantly after bariatric surgery.) The researchers plan to report hormonal changes in a separate study.

Originally published on Live Science.

Rachael Rettner

Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.