AT OBESITY WEEK 2014
BOSTON (FRONTLINE MEDICAL NEWS) – Moderately obese patients who either don’t want or don’t qualify for bariatric surgery may be able to benefit from a reversible procedure using an investigational intragastric balloon.
In a randomized controlled trial, patients with a body mass index (BMI) from 30 to 40 kg/m2 who were assigned to receive a dual intragastric balloon (ReShape Duo) plus a diet and exercise regimen lost 25% of their excess weight, compared with only 11% of patients assigned to undergo a sham procedure plus diet and exercise, reported Dr. Jaime Ponce, medical director for the Bariatric Surgery program at Hamilton Medical Center in Dalton, Ga., and Memorial Hospital in Chattanooga, Tenn.
“The ReShape procedure is a reversible intervention that can be used in patients with BMI from 30 to 40 who are not ready for surgery or did not qualify for surgery. It was effective, as it showed a 2.2 times greater weight loss, compared with the diet group,” he said at the meeting presented by the Obesity Society and the American Society for Metabolic and Bariatric Surgery.
At 48 weeks, patients sustained on average 65% of the weight loss they had achieved at week 24, he said.
Two-chamber device
The dual intragastric balloon consists of two silicone balloons connected by a flexible shaft to provide migration resistance. The deflated device is inserted over a guide wire into the stomach in a transoral endoscopic procedure. Once in place, the device is inflated with a saline and methylene blue solution by a powered pump, up to a total volume of 750 to 900 cc. The mean duration of the procedure is 8 minutes Dr. Ponce said.
Barring problems, the device is left in place for 6 months and is then emptied, captured with a standard endoscopic snare, and removed, a process that takes a mean of 14 minutes.
Dr. Ponce and colleagues enrolled obese adults with a BMD from 30 to 40 kg/m2 and one or more obesity-related comorbidities to undergo either balloon insertion, diet and exercise (187 patients), or a sham procedure plus diet and exercise (139).
All patients had monthly counseling on diet and exercise as per obesity management guidelines from the National Heart, Lung and Blood Institute published in 2000.
The participants were blinded to treatment assignment for 24 weeks, at which time patients in the diet group could exit the study or, if they wished, receive the balloon and continue in the study for an additional 24 weeks. Patients who initially received the balloon remained in the study and continued diet and exercise during the same 24 weeks.
Balloons were successfully inserted in 99.6% of cases, and all inserted balloons were retrieved successfully. Three patients had serious adverse events related to retrieval: one case of pneumonia requiring hospitalization and antibiotics, one contained perforation of the cervical esophagus, also requiring hospitalization and antibiotics, and one proximal esophageal mucosal tear requiring hemostatic clips.
The trial met its primary endpoint of a greater than 7.5% difference between the balloon and control groups, with balloon receivers having a mean excess weight loss of 25.1%, compared with 11.3% for controls (P = .0041) in an intention to treat analysis, and 27.9% vs. 12.3%, respectively, in patients who completed the study (P = .0007).
At 48 weeks, patients initially assigned to receive the balloon had significant improvements in hemoglobin A1c, cholesterol levels (HDL up, LDL down), systolic and diastolic blood pressures, and waist and hip circumference.
Among all implanted participants, 11.6% had mild to moderate nausea and vomiting on day 3, which gradually declined over the study. In addition, 34.1% had abdominal pain they rated as mild to moderate on a visual analog scale,
The safety analysis, including all 264 patients who received the balloon initially or at week 24, showed no deaths, balloon migration, obstructions, or required surgeries. Most adverse events were gastrointestinal in nature, mild to moderate, and resolved within the first 30 days.
Investigators saw gastric ulcers in 93 of the 264 patients who received the balloon. They determined the cause to be the distal tip of the device contacting the incisural wall, where more than 95% of the ulcers were observed. The manufacturer made minor changes to lower the profile of the tip and make it smoother and softer, resulting a “dramatically reduced ulcer rate and size,” Dr. Ponce said.
In all, 15% of the balloons were retrieved early, 6% after 2 months, associated with ulcers, and 9% within 2 months of insertions because of device intolerance. The authors found shorter patients had significantly fewer problems when the balloons were inflated with 750 cc rather than 900 cc.
The balloons spontaneously deflated in 6% of participants, signaled by the presence of blue-green urine in about two-thirds of these patients. All of the devices in these cases were successfully retrieved without problems, Dr. Ponce said.
Dr. Manoel P. Galvao Neto of the Gastro Obeso Center in São Paulo, Brazil, the invited discussant, commented that the study was well designed and carried out, with a clear methodology and frank assessment of adverse events, and it met all of its primary endpoints.
Excretable balloon
In a separate pilot study, eight patients who swallowed a limited-duration, self-emptying balloon (Elipse) that is excreted through the bowel lost an average of 12% of excess body weight, reported Dr. Evzen Machytka of the department of clinical studies at the University of Ostrava, Czech Republic.
For the trial, investigators used a custom device designed to self-deflate in 6 weeks. The device is packaged in a capsule and is attached to a thin capillary tube. The patient swallows the balloon without endoscopy or anesthesia. The capsule dissolves quickly, and when gastric positioning of the balloon is confirmed with x-rays, the balloon is then filled with 450 mL saline, in a process that takes approximately 15 minutes.
After a prespecified time (6 weeks, in the case of the trial, 3 months in the device intended for market) a self-releasing valve opens, the balloon empties and is then excreted normally, Dr. Machytka said.
In the pilot trial, all eight balloons were safely excreted. One had deflated early because of a manufacturing defect, and one asymptomatic patient withdrew from the study because she “no longer enjoyed eating.” In both cases, the balloons were punctured via endoscopy but not retrieved, and were excreted normally in the stool 4 days later.
The investigators hope to receive marketing approval for the device in 2015, Dr. Machytka said.
