AT DDW 2016
SAN DIEGO (FRONTLINE MEDICAL NEWS) – Device companies are working hard to bring obesity management to the endoscopy suite.
The field is called endobariatrics, and its goal is to fill the gap between surgery and pharmacotherapy. Drugs and lifestyle counseling don’t work too well, but a lot of people don’t want to go under the knife, so something is needed in the middle. Endobariatrics has the potential to be a boon for both obese patients and gastroenterology practices.
Several new investigational devices and approaches were showcased at the annual Digestive Disease Week; some “are beginning to approach the kind of results we see with surgical techniques,” said Steven Edmundowicz, MD, medical director of the University of Colorado Digestive Health Center, Aurora.
“We are seeing a tremendous amount of development in this space, but it’s early, and we have to be cautious,” he said. There have already been a few disappointments, including the EndoBarrier , a fluoropolymer liner anchored in the duodenal bulb and unfurled down the duodenum to block food absorption. A key U.S. trial was recently halted due to liver abscesses.
Dr. Edmundowicz reviewed the latest developments presented at DDW.
Self-assembling magnets for dual-path enteral anastomoses
The goal of the GI Windows system is to create a partial jejunoileal, side to side bypass without surgery. A 28-mm magnet ring is introduced to the ileum by colonoscopy, and a second ring to the jejunum by endoscopy. The rings snap together and tissue caught between them dies from pressure necrosis, leaving patients with a jejunoileal communication. Once food reaches that point, it either diverts through the anastomosis or continues past it down the digestive track. The magnets pass after the anastomosis forms in a week or so.
In a 6-month feasibility study from the Czech Republic, 10 obese patients lost 28.3% of their excess weight without diet restrictions. Those with diabetes had a mean hemoglobin A1c drop of 1.8%, and normalization of fasting blood glucose levels. The procedure took just over an hour and a half after the first five cases.
“I am very excited about [this]; I really want to see where the data are going,” Dr. Edmundowicz said.
Duodenal mucosal resurfacing
The idea of the Revita System (Fractyl) is to ablate “diabetic mucosa” in the duodenum so that normal mucosa can replace it. Saline is injected endoscopically under a portion of the duodenal mucosa to lift it off the muscularis; once isolated, the mucosa is destroyed – some in the audience thought “cooked” was a better word – by exposure to a hot water balloon catheter threaded into the lumen.
Thirty-nine overweight or obese type 2 diabetics had a 1.2% improvement at 6 months from a baseline hemoglobin A1c of 9.6% in a series from Santiago, Chile. Weight loss was modest in the trial; the system is being developed for type 2 diabetics.
There is some histologic support for the notion of a diabetic mucosa with both structural and hormonal aberrations, but it’s unclear if it’s a sign or cause of sickness. Even so, “the mucosa regenerates” and won’t be diabetic “for a while” after the procedure, said investigator Manoel Galvao Neto, MD, of the Gastro Obeso Center, São Paulo.
Inflating a balloon in the stomach to make people feel full isn’t new, but the notion of putting the balloon into a capsule that patients can swallow and inflating it through a tether is a more recent notion.
The Obalon (Obalon Therapeutics) is one such device. In an unblinded, sham-controlled trial with 336 obese patients, subjects who got the 250-mL, nitrogen-filled Obalons – most received three – lost about 3% more of their total body weight at 24 weeks than those who did not. Although swallowed, Obalon is removed endoscopically. Meanwhile, 34 obese patients who swallowed the 550-mL, fluid-filled Elipse balloon (Allurion) had a total body weight loss of 9.5% and mean excess weight loss of 37.2% at 4 months, by which time Elipse deflates on its own and passes without endoscopic retrieval.
“This is a very promising approach. I am very excited about digested balloons,” said Dr. Edmundowicz, an investigator in the Obalon study.
Endoscopic sleeve gastroplasty
Endoscopic sleeve gastroplasty duplicates sleeve gastrectomy with stitches placed endoscopically to seal off the greater curvature of the stomach; functionally, patients are left with a narrow sleeve of a stomach. In a multicenter series presented at DDW, 242 patients had a mean total body weight loss of 19.8% at 18 months, with a low incidence of complications. “Weight loss appears to be continuing,” Dr. Edmundowicz said. Investigators used the Apollo OverStitch (Apollo Endosurgery) to place the sutures.
With Food and Drug Administration approval on June 14 , AspireAssist (Aspire Bariatrics) is probably the best known of the newer approaches. Patients drain a portion of their meals through an endoscopically placed percutaneous gastrostomy tube a half hour or so after eating. It takes 5-10 minutes. The agency is eager to keep it out of the hands of bulimics.
One-year data were reported at DDW; 111 obese AspireAssist subjects lost a mean of 37.2% of their excess weight versus 13% in 60 patients randomized to lifestyle counseling alone.
“It may not be aesthetically pleasing, but it certainly works. It’s a viable technology,” said Dr. Edmundowicz, who was an investigator.
The studies were funded by companies developing the devices and techniques. Dr. Edmundowicz has stock options, or is a consultant or researcher, Aspire, Obalon, GI Dynamics, Elira, and other firms.