Implanted Device Tested as New Weight-Loss Option

Vagal nerve blocking device and lifestyle changes slightly more effective than lifestyle changes alone

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) With obesity on the rise worldwide, solutions like bariatric surgery to combat life-threatening medical conditions linked to being obese have become more common. New research looked at the effectiveness of another weight-loss option.

Because bariatric surgical options can have harmful side effects, researchers tested a medical implant that regulates the digestive system to try to avoid those effects. 

The authors of the recent study found that the device was safe but only slightly more effective for weight loss than lifestyle changes like diet and exercise.

"Discuss weight-loss options with a gastroenterologist."

The study was written by Charles Billington, MD, of the Division of Endocrinology and Diabetes at the VA Medical Center in Minneapolis, MN, and colleagues.

Focused on patients at risk of death related to obesity, the study examined what's called a vagal blockage.

In a vagal blockage, electrodes are placed on the vagus nerve, which helps regulate the digestive tract. The electrodes deliver 12 hours a day of stimulation to help regulate appetite and metabolism.

The study authors recruited 239 patients with a body mass index (BMI) between 35 and 45. BMI is a height-to-weight ratio. A BMI over 25 is considered overweight.

Patients also had at least one obesity-related medical condition, such as type 2 diabetes or high blood pressure.

Of the study group, 162 patients had a vagal nerve blockage device put in their bodies, while 77 received a so-called “sham device” that did not affect the vagal nerve.

In the study group with the device, patients lost an average of 9.2 percent of their body weight. In the group with the sham device, patients lost 6 percent.

After a year, patients with the nerve block lost more weight than patients in the sham-device group.

The patient outcomes fell short of the weight-loss goals set prior to the study.

Also, the patients with the device more frequently reported "mild or moderate" heartburn and stomach pain.

The authors called for more study of the device “to assess long-term durability of weight loss and safety.”

In a companion editorial, David Arterburn, MD, MPH, and David Fisher, MD, noted that "the sham group lost a substantial amount of weight."

That outcome was partly due to daily self-monitoring and lifestyle counseling, according to the study.

"Vagal nerve blockade plus moderately intensive lifestyle counseling does not appear to be much more effective than an intensive lifestyle program," the editorial authors wrote.

The study and editorial were published online Sept. 2 in JAMA.

EnteroMedics, Inc., funded the study. Some study authors disclosed consultancy and other roles with private companies, including EnteroMedics.

Review Date: 
September 2, 2014
Last Updated:
September 4, 2014