Obese Patients Achieved Weight Loss with Vagus Nerve Blockade (vBloc)
Reduced comorbid risk factors and improved satiety reported with minimal side effects, using the first new obesity therapy to receive FDA device approval in 9 years
Bringing the prospect of improved health to people who are struggling with obesity, a recently approved pacemaker-like device, the vagal nerve blockade (vBloc®), prompted a clinically significant weight reduction in individuals followed for 2 years, according to the most recent findings from the ReCharge Trial. The vBloc with the Maestro® Rechargeable System (EnteroMedics, St Paul, MN) is the first device to receive U.S. Food and Drug Administration (FDA) approval to treat obesity since 2007.
“Patients treated with the [vBloc] device were able to maintain weight loss and achieve meaningful improvements in their health,” said Caroline Apovian, MD, FACP, FACN, lead author, and a professor of medicine and pediatrics at Boston University School of Medicine, based on findings published in the journal, Obesity Surgery.
Until last year, patients with moderate to severe obesity who were trying to lose weight had three options: (1) diet and exercise, (2) medication, or, (3) bariatric surgery. The value of dietary restriction, with or without exercise, has proven insufficient for most individuals in the long term, particularly those with comorbid conditions that necessitate a consequential weight loss where as medications typically come with serious, undesirable side effects.
While bariatric surgical procedures have been an effective solution for those who are significantly overweight, bariatric surgery may be viewed as too drastic despite a patient's urgent need to lose weight, and introduces a significant risk of complications, and so cannot be advised for all who seek a surgical method to effectively improve their health.
In addition to reports of better control over eating habits, there were significant reductions in patients’ risk for cardiovascular disease, including reduced waist circumference, blood pressure, serum cholesterol, and HbA1c levels. The most common side effects were heartburn and dyspepsia, affecting about 4% of patients, and most complaints resolved by 24 months.1
“Vagal nerve blocking—which has a success rate somewhere in between bariatric surgery and medication—isn’t likely to replace all other weight loss treatment options,” said Dr. Apovian, who is also director of the Nutrition and Weight Management Center and the Nutrition Support Service at the Boston Medical Center. “But weight regain is a common problem for people who use obesity drugs, which are often discontinued due to side effects, or those who have temporary interventions like the gastric balloon."
"Vagal nerve blocking is a good option for patients who are morbidly obesity and are seeking a permanent solution that is more effective than lifestyle modification alone, but has a minimum risk of complications than anatomy-altering bariatric surgery, with a rate of more than 20%,” said Dr. Apovian.
New Device Seeks Its Place in the Obesity Treatment Landscape
Two-year results for vBloc were not compelling enough to recommend the treatment over bariatric surgery for obese patients, particularly those with significant comorbidities, according to Michael Gonzalez-Campoy, MD, PhD, FACE, Medical Director and CEO of the Minnesota Center for Obesity, Metabolism and Endocrinology.
“The weight loss achieved with anatomy-altering surgery is more profound, and more durable,” said Dr. Gonzalez-Campoy, who noted that, depending on the procedure, excess weight loss ranges from 30% to more than 80% with bariatric procedures.
The vBloc device was placed laparoscopically into the abdomen to function in a manner similar to a pacemaker, sending intermittent electrical pulses to the vagus nerves at the gastroesophogeal junction.
“However, vagal blocking may offer an alternative to procedures, such as gastric banding, in which reduced absorption of nutrients can exacerbate other medical problems,” said Dr. Gonzalez-Campoy.
The vBloc therapy is currently indicated for adults with a BMI 35 to 45 and targeted to those with at least one obesity-related complication, such as diabetes, elevated lipids, or hypertension, who have already tried, unsuccessfully, to lose weight in a supervised weight management program.
Additional follow-up studies are planned to track the device’s safety and efficacy for five years as a stipulation of FDA approval. The study was funded by EnteroMedics Inc. to whom Dr. Apovian is a consultant. Dr. Gonzalez-Campoy reports no conflicts.