A ‘Pacemaker’ for Obese Patients

The FDA has approved a new device akin to a pacemaker, called VBLOC, which is designed for very obese adults, or those with a body mass index (BMI) of 40 to 45 kg/m² Candidates for the device also include obese adults in the 35 to 39 kg/m² range who have an obesity-related health condition, such as hypertension or high cholesterol. The neurostimulator is specifically intended for patients who have failed weight loss programs over the prior 5 years. VBLOC vagal-blocking therapy is delivered by the Maestro® System (EnteroMedics, St. Paul, MN). This transplantable rechargeable device works by intermittently blocking the vagus nerve. FDA approval followed the results of the ReCharge Study, a randomized, double-blind, sham-controlled intention-to-treat trial involving 162 adults who received the device and 77 who received a sham device (JAMA 2014; 312:915). At the end of 12 months, patients treated with VBLOC therapy had lost an average of 24.4% of their excess weight. Severe side effects occurred in 3.6% of patients; these included device malfunction, implant site pain, and hospitalization for surgical complications. Other more minor side effects included pain at the neuroregulator site, abdominal pain, and heartburn. VBLOC therapy is contraindicated for patients with cirrhosis of the liver, portal hypertension, esophageal varices, or clinically significant hiatal hernia. It is also contraindicated for patients who will require magnetic resonance imaging, patients at risk for surgical complications, and those who already have a permanently implanted electrically powered medical device, such as a pacemaker or other type of neurostimulator.