Dieting Device Tricks Brain into Feeling Full

In mid-January a novel obesity treatment surfaced in the public market. There are no constricting bands or rerouted intestines; the device hinges on the “feeling” of hunger—or lack thereof. Recently green-lighted by the FDA, the device, called the Maestro Rechargeable System, uses a pacemaker-like approach to curb appetite. It targets part of the body called the vagus nerve, which controls a handful of vital human functions, like heartbeat and breathing. But Entero Medics, producer of the device, focuses on its role as the hunger nerve, capitalizing on its ability to regulate brain-body satiety.

Doctors and researchers working with the Maestro System promote it as a new, safe and effective option in treating obesity. And though it’s an intriguing prospect, some clinicians grapple with the device’s feasibility as a practical option for most obese patients. For some, the sheer novelty is enough to be wary, but most concerns center on a hefty price tag and a modest weight loss.

But regardless of the system’s future, it’s the first FDA-approved obesity device since 2007 and a positive step in advancing obesity treatment and technology. Since the American Medical Association officially declared obesity a disease in 2013, researchers and patients are increasingly treating it as such, rather than a lack of self-restraint.

“It’s like having high blood pressure. You don’t blame somebody for having high blood pressure, you treat it,” says Susan Fried, Professor of Endocrinology, Diabetes and Nutrition at Boston University’s School of Medicine. “But we do blame people for being obese. I think people mistakenly assume it’s all environment since we can’t find one gene that’s responsible for obesity, and that’s not true.”

The Maestro Rechargeable System treats obesity with a surgically implanted chip paired with a battery pack and coiled portable charger. After a full charge, the device’s power lasts 2-3 days—which is more than most can say for their cell phones. But it’s the patient’s responsibility to keep a full charge as long as they have the device, which potentially, is the rest of their life.

Upon implantation, surgeons suture the device’s electrodes in a specific region of the lower abdomen, isolating the portion of the vagus nerve that innervates the stomach. These electrodes periodically send impulses into the nerve and block the signal from the stomach to the brain that causes the “hungry” sensation, hoodwinking the body into thinking that it’s full.

This electrical strategy is known as VBLOC therapy (vagal blocking therapy), and though stimulating the vagus nerve to improve health isn’t a new concept, doctors don’t fully understand how these electrical pulses stop vagal communication. They do, however, know that complete blockage of the vagus nerve is ineffective. Other mechanisms in the body recognize the loss of appetite signal and attempt to compensate for the deadpan nerve. That’s why the device works in pulses instead of one giant electrical blockade.

But the pulses aren’t the same for everyone—every patient has a different pulse-to-weight-loss ratio, and the trick is striking the right balance. During the clinical trials, doctors monitored patients’ weight loss closely, tailoring millivolts to best elicit feelings of fullness.

“The pulses aren’t random. They’re dependent on the patient,” says Dr. Caroline Apovian, Director of Nutrition and Weight Management Center at Boston Medical Center. “Patients follow up with their doctors to hit the sweet spot of pulse generation,” she adds. After doctors insert the device, they tune each patient’s electrical impulses based on how hungry they feel. Descriptors vary, but doctors monitor patients for feelings of fullness, pressure and heartburn to gauge satiety.

Under the umbrella of bariatric surgery, the Maestro Rechargeable System is the safest, but is most modest in weight loss. Over a one year period in a clinical trial called ReCharge, patients with the device lost an average of 9.6% of their total body weight. For contrast, the gastric bypass, currently the “gold standard” of bariatric procedures, stands out for its dramatic weight loss effects—around 33% of total body weight. But in terms of safety and post-surgery complications, the Maestro System is the better option.

“This surgery is quite possibly the safest thing we have right now,” says Dr. Sanjani Shah, Assistant Professor of Surgery at Tufts University School of Medicine. “It’s completely reversible—we’re not cutting or pasting anything. There’s nothing being rerouted.”

During the ReCharge trial, less than 4% of the 233 patients enrolled experienced severe problems ending in re-hospitalization or removal of the device. For the most part, patients who did report side effects complained of moderate ailments like bloating, nausea or upset stomach. But for some, like local Boston patient, Mike Magnant, the device seems virtually flawless.

“I’ve not been nauseous, no headaches, never felt dizzy. I don’t have any restrictions on what I can eat,” Mike says.

After hearing an ad for the Maestro System on the radio, Mike enrolled in Entero Medics’ first clinical trial. He fit the criteria: between 18 and 65 years old, unsuccessful long-term weight loss in other structured programs, and a Body Mass Index between 35 and 45 kg/m2 (between 260 and 330 lbs for a 6-foot male adult). After having the device for three years, Mike says he wouldn’t give it back even if the FDA hadn’t approved it.

“To lose 70 pounds and not gain it back? There are so many benefits to losing that weight, and to me, the best part is keeping the weight off,” he says. “This is forever for me.”

The patients from the Maestro System’s clinical trials have, on average, maintained the weight lost. But the trials are still in relatively early stages, and only time can tell if the system will prove effective over a lifetime.

While Mike’s experience is successful, it’s not necessarily representative of all patients with the device. Some doctors speculate that VBLOC therapy may be more of a fad than an emerging go-to in obesity treatment. Dr. Lee Kaplan, Associate Professor of Medicine at Harvard and Director of the Massachusetts General Hospital Weight Center, puts it in perspective when he points out the patient-to-patient variation that inevitably comes with any disease treatment. In this case, patients that receive the device have no way to tell if their weight loss will be above, below, or on par with the average.

“What we really need is a parameter predicting how well the person may do with the device, but as of now we have no evidence for that,” says Dr. Kaplan. “So the question is, ‘Is it the best idea to use this device, which requires surgery?’ I think it’s going to be a hard sell, given the cost.”

Though Entero Medics hasn’t landed on a price or whether insurance will cover part or all of the cost, speculative prices hover around $15,000-$30,000. In considering the device’s relatively slight results, some patients may find it too expensive. But Entero Medics highlights the safety and sustainability of weight loss as key players in their future push to market.

Currently, doctors and researchers are continuing to follow patients with the device in a five-year, post FDA-approved study to monitor sustained and continued weight loss and any complications that may surface.

Looking forward, Dr. Shah hopes the Maestro Rechargeable System continues to gain attention from the public as an option for obesity treatment. “I’d be really happy if it got out in the public eye and patients understand the option—to say hey, this is a great other option if you’re considering surgery in morbid obesity.”