Vagal Blocking Therapy: A Safe, Reversible, Compatible Option for Treating Obesity

A Message from Dr. Scott Shikora

Scott Shikora, MD, FACS, is Director, Bariatric Surgery, Brigham and Women’s Hospital, and Professor of Surgery, Harvard Medical School, Boston, Massachusetts. He is a past president of the American Society for Metabolic and Bariatric Surgery.

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Dear Readers:
Since I entered the field of bariatric surgery in 1991, I have performed thousands of procedures, and have thus witnessed their evolution. I believe that our current conventional procedures (i.e., Roux-en-Y gastric bypass [RYGB], laparoscopic sleeve gastrectomy [LSG], and duodenal switch [DS]) are being done safely and producing good results. Despite this, the fact remains that less than one percent of potential candidates in the United States are choosing surgery. No matter how safe and successful these procedures have become, some patients simply do not want to have surgery for multiple reasons. I believe that the average individual still views bariatric surgery as dangerous or radical because it results in severe alterations of the gastrointestinal tract. They might also not choose surgery because they are unwilling to make long-term changes to their lifestyle like adhering to draconian diets. Another reason—fear—a topic Dr. Raul Rosenthal, current American Society for Metabolic and Bariatric Surgery (ASMBS) President has been discussing lately.

The 99 percent of patients who are not coming forward for bariatric surgery are likely looking for alternatives. Today, we have several new therapies approved by the Untied States Food and Drug Administration (FDA) that may attract and help this patient population. One such technology is vagal nerve blocking therapy (vBloc®, EnteroMedics® Inc., St. Paul, Minnesota) as delivered through the Maestro® Rechargeable System (EnteroMedics® Inc.).
The vBloc therapy works by providing intermittent blockade of the vagus nerve, which plays important roles in unconscious body processes, such as heart rate regulation, food digestion, appetite signaling, and body weight. Three major benefits of vBloc are its safety, reversibility, and compatibility with lifestyle. Complications are minimal, and the device can be removed safely, which allows patients to later pursue surgery. It may also offer a treatment option for patients who for various reasons, cannot have conventional surgery. Other patient populations that vBloc might be best suited for are adolescents, who may not want an irreversible procedure, and the elderly, who may be afraid of the risks associated with any major operation.

Trials comparing vBloc to sham therapy[1,2] have demonstrated safety and efficacy with weight loss outcomes between 25 and 35 percent excess weight loss (EWL). This month, results from a large, randomized, prospective double-blind sham controlled trial called ReCharge[3] demonstrate superior weight loss with vBloc therapy versus sham device in individuals with moderate obesity (35–40kg/m2). Although not in the same league as conventional bariatric surgical procedures, this weight loss (average 33%EWL) is still significant and results in comorbidity improvement.

Like other bariatric surgery procedures, the vBloc device has improved throughout the years. An early generation of the device as examined in the EMPOWER trial[1] required the patients to wear a belt that contained the power source. This design presented a few challenges. First, device efficacy was largely dependent on the patient’s adherence to wearing the belt. Second, it was determined that even the sham-controlled group received some vagal nerve blocking when the device completed self checks.

The latest ReCharge study tested a new generation device that sought to fix these issues. For instance, the new model contained an internal power source that was programmed to activate a set number of hours, and the patient is only responsible for recharging the device. Also, the sham patients did not have leads implanted on the anterior and posterior vagal nerve trunks.

Our future goals are for the device to be smaller, less expensive, and as easy as possible for the patient to manage. We are also looking at how vBloc therapy works in conjunction with behavior modification. Previous studies included only minimal behavioral therapy because they were meant to examine the device without confounding variables like diet and lifestyle changes. From the history of bariatric surgery, we understand that operations work best with additional dietary and behavioral support. The vBloc therapy now includes a comprehensive, interactive exercise and behavior program called vBloc Achieve. In addition, bariatric programs that implant the device will be encouraged to follow patients in the same way they would after LSG or RYGB.
Currently, we are continuing to follow patients from the previous trials to determine the durability of vBloc therapy. We also hope to conduct new studies as we are only scratching the surface of understanding the optimal current pattern and device design. Efforts are now being focused on urging insurance coverage. In February 2016, Winthrop-University Hospital, Mineola, New York, became the first employer in the US to offer coverage for vBloc Therapy for its employees. We hope that other carriers, especially the major insurance companies, will follow suit.

It’s an exciting time in our field, and I am proud to be a part of the research into new therapies that can potentially help many patients who suffer from overweight and obesity.

Sincerely,
Scott Shikora, MD, FACS

References
1.    Sarr MG, Billington CJ, Brancatisano R, et al. The EMPOWER study: randomized, prospective, double-blind, multicenter trial of vagal blockade to induce weight loss in morbid obesity. Obes Surg. 2012;22:1771–1782.
2.    Ikramuddin S, Blackstone RP, Brancatisano A, et al. Effect of reversible intermittent intra-abdominal vagal nerve blockade on morbid obesity: the ReCharge randomized clinical trial. JAMA. 2014;312(9):915–922.
3.    Morton JM, Shah SN, Wolfe BM, et al. Effect of vagal nerve blockade on moderate obesity with an obesity-related comorbid condition: the ReCharge study. Obes Surg. 2016;26(5):983–989.

Disclosures: Dr. Shikora is Chief Medical Officer and Vice President of EnteroMedics, St. Paul, Minnesota.

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