The New Device to Treat Obesity: Is It for You?

Reviewed by Brunilda Nazario, MD on January 16, 2015
From the WebMD Archives

Jan. 16, 2015 -- The FDA just approved the first new obesity device since 2007. 

The Maestro Rechargeable System is a pacemaker-like implant that sends electrical pulses to the vagus nerve. The nerve extends from your brain to your stomach. It's involved in signaling the brain about whether the stomach is full or empty.

A committee of outside advisors to the FDA had concluded that the benefits of the Maestro System outweighed its risks. Most of the panel members agreed that the device was safe, but they were less enthusiastic about whether it worked: Four voted “yes” and five voted “no.”

WebMD asked two obesity experts involved in clinical trials of the device as well as the manufacturer, EnteroMedics, about how the Maestro System is supposed to be used and who might benefit.

Q. What parts make up the Maestro System?

A. It consists of a pacemaker-like electrical pulse generator, wire leads, and electrodes that are implanted in the abdomen. This surgery is a 60- to 90-minute outpatient procedure done while you're under general anesthesia, says EnteroMedics spokeswoman Jody Dahlman.

Q. How does it work?

A. The system is programmed to deliver a pulse -- 5 minutes on and 5 minutes off -- to the vagus nerve during your waking hours, and it's supposed to turn off during the hours you sleep, Dahlman says. 

Q. Who's a candidate for the Maestro System?

A. The FDA approved the device for the treatment of obese adults who have a body mass index (BMI) of at least 40, and for those with a BMI of at least 35 who have an obesity-related condition, such as high blood pressure or high cholesterol. Candidates are supposed to have tried to lose weight in a supervised weight-management program within the previous 5 years.

But once the FDA approves a device or a drug, doctors are free to prescribe it to any patient they think might benefit. The device could prove to be useful in helping extremely obese people lose some weight so they can more safely undergo gastric bypass surgery, says Caroline Apovian, MD. She's the director of nutrition and weight management at Boston Medical Center. The Maestro System also might help enhance weight loss after gastric bypass surgery, she says.

“I don’t have a good feel for who are going to be the ideal candidates,” says Ken Fujioka, MD, an obesity specialist at the Scripps Clinic in San Diego. Fujioka helped present data for EnteroMedics at the FDA advisory committee meeting last June. “You’re looking at weight loss that’s relatively similar to weight-loss drugs, and yet, you have to have a surgery.”

People who can’t tolerate weight-loss medications might benefit from the device, as might people with diabetes or pre-diabetes, he says. In clinical trials, the Maestro System appeared to have a good effect on blood sugar control on top of weight loss, Fujioka says.

“It does take a motivated patient,” he says. “You have to take care of this device. You have to charge it once or twice a week.” If the battery is allowed to totally drain, you need to see your doctor to have it reprogrammed, he says.

Q. How long is it left in place?

A. “This is intended to be a partner for life with patients,” Dahlman says. Some people have had it in place more than 7 years, she says. The battery lasts at least 8 years, at which point “it can be replaced relatively easily, probably with a local anesthetic.”

Q. What are the side effects?

A. In the clinical study, they included nausea, pain at the site the device was implanted, vomiting, surgical complications, heartburn, problems swallowing, belching, mild nausea, and chest pain, according to the FDA. “Some patients will feel a slight tingling when they first start the therapy, but it goes away when their body adjusts to the sensation,” Dahlman says.

Q. Why did the majority of the FDA advisory panel think it wasn’t effective?

A. In a clinical trial, the Maestro System “achieved exactly the amount of weight loss we thought we would get” after 1 year, Dahlman says.

However, one group of participants received the device, but (unbeknownst to them) it wasn't activated. Still, they lost more weight than expected. So the difference between those people and the group of participants whose devices got activated wasn’t that big after 1 year, Apovian says.

At that point, people who got the turned-on devices had lost only 8.5% more of their excess weight than those in the other group. The goal was for them to lose at least 10% more of their excess body weight, according to the FDA.

“If you think about it, it makes sense, because they [people who got a device that wasn't activated] underwent a surgical procedure,” Apovian said. “That is a group of patients who are extremely committed to getting weight loss. We think the placebo effect was very, very strong.” But after the first year, the people who got the device that wasn't turned on started gaining weight, while those who received the activated version continued to lose, she says.

All of the people in the clinical trials received counseling about diet and exercise, Fujioka says.

But the device alone won’t cause healthy weight loss. People do have to eat less and exercise more, Fujioka says. “This should help the person stay on track,” he says, because it should increase the feeling of fullness.

Q. How much does the Maestro System cost?

A. EnteroMedics spokeswoman Eliza Schleifstein says she can't provide an exact number. She did say that the price would fall between that of gastric bypass surgery and a gastric band device. Such surgeries can cost, on average, between $20,000 and $25,000, according to the National Institutes of Health.

Q. How soon can I get it?

A. At first, the Maestro System will be available only at obesity treatment centers that participated in the main clinical trial of the device, Schleifstein says. It won’t become more widely available until private and public insurers agree to cover it, and EnteroMedics can't say when that might be, she says.

Show Sources


News release, FDA.

News release, EnteroMedics.

Jody Dahlman, EnteroMedics.

Caroline Apovian, MD, director of nutrition and weight management, Boston Medical Center.

Ken Fujioka, MD, Scripps Clinic.

Eliza Schleifstein, EnteroMedics.

© 2015 WebMD, LLC. All rights reserved. View privacy policy and trust info