SAN FRANCISCO – Endoscopic treatments for obesity are under-utilized but represent an opportunity for gastroenterologists to help address the metabolic epidemic that affects up to 40% of people in the United States, according to a presentation reviewing these techniques.
Lifestyle modification is the first intervention, but results in just a 5% average weight loss, according to Allison Schulman, MD, MPH, who discussed these options at the 2022 AGA Tech Summit sponsored by the AGA Center for GI Innovation and Technology. Although surgical interventions induce more weight loss and greater improvement of metabolic outcomes, they come with significant risks and many patients are reluctant to pursue them, she added. In fact, fewer than 1% of obese individuals who qualify for bariatric surgery ultimately undergo it.
Dr. Schulman emphasized another option: Endoscopic bariatric therapies fill this void in between those two extremes, as they are clearly less invasive” said Dr. Schulman, who is an assistant professor of gastroenterology and hepatology at the University of Michigan, Ann Arbor. “They may appeal to those who do not qualify or do not want bariatric surgery. They also could bridge a critical gap in the treatment of obesity, as they reach patients earlier, at BMIs [body mass indexes] where they may not be surgical candidates. Furthermore, these therapies are oftentimes repeatable and commonly can be used in combination [with other weight loss approaches].”
Endoscopic therapies for obesity include devices that occupy space in the stomach, such as intragastric balloons, gastric remodeling procedures like endoscopic sleeve gastroplasty (ESG), and aspiration therapy.
Potential candidates for noninvasive approaches include patients with a BMI over 30 kg/m2 who have not lost sufficient weight through nonsurgical methods or those who do not want to undergo surgery or require a bridge therapy to surgery.
Fluid-filled balloons can be placed and filled to an appropriate volume. One network meta-analysis found that fluid-filled balloons were more likely to lead to weight loss, but also more likely to be removed due to intolerance. She also noted that the Elipse balloon (Allurion Technologies) is designed to be swallowed and thus avoid procedures entirely; it is currently under review by Food and Drug Administration.
Although balloons are linked to 7%-10% weight loss in some studies and reviews, Dr. Schulman said, “we know … that the majority of these lead to much more weight loss in clinical practice, oftentimes closer to 13%-%15.”
One review found that balloons also lead to improvement in obesity-related comorbidities, compared with conventional nonsurgical approaches, and this benefit extends past 1 year. A study of 21 patients with nonalcoholic steatohepatitis (NASH) treated with intragastric balloons found that 90% had an improvement in nonalcoholic fatty liver disease activity score, with a median drop of 3 points, and 80% had a drop of at least 2 points. Of these patients, 50% also had an improvement in fibrosis determined by magnetic resonance elastography.
Balloon therapy should be highly individualized, according to Dr. Schulman.
Dr. Schulman also described ESG, which uses sutures to remodel the stomach and reduce volume by up to 70%. She outlined studies and reviews, such as those from Sharaiha and colleagues and Hedjoudje and colleagues, showing that ESG leads to significant and sustained weight loss. The procedure was also quite safe, with one large, single-center study showing that both fever and significant blood loss each occurred in less than 1% of patients (Gastrointest Endosc. 2019 Jun;89[6]:1132-8), while the systematic review and meta-analysis from Hedjoudje and colleagues found an adverse event frequency of 2.2%.
In a matched control study, laparoscopic sleeve gastrectomy led to more weight loss, but ESG had fewer adverse events (5.2% versus 16.9%; P < .01) and had a greater effect on gastroesophageal reflux disease.
ESG can be effective when repeated, while surgical revisions are associated with much higher morbidity, according to Dr. Schulman.
During her presentation, Dr. Schulman mentioned the AspireAssist device developed by Aspire Bariatrics, which is similar to a percutaneous endoscopic gastrostomy (PEG) tube. It leads to the removal of about 30% of calories consumed during a meal, with patients instructed to aspirate 20-30 minutes after a meal, two to three times a day. It gained Food and Drug Administration approval on the strength of the PATHWAY study, which showed significant weight loss.
“But perhaps more impressive is the overall patient satisfaction and willingness to recommend this device to others,” said Dr. Schulman.
Another approach she described is the transpyloric shuttle (TPS), which leads to faster filling times and delayed gastric emptying, though it must be removed endoscopically at 12 months.
Dr. Schulman also discussed endoscopic bariatric and metabolic therapy. This approach is currently a primary therapy for obesity, and is in development for the treatment of diabetes and non-alcoholic fatty liver disease. The approach is predicated on the idea that obesity is a disorder of energy homeostasis, and that enteric neurons in the small bowel are key players, possibly through reduced production of as yet unknown signaling molecules, leading to insulin resistance. It’s also known that diets high in fat and sugar alter the duodenum, which causes changes in nutrient signaling to the brain.
“It’s thought that this leads to duodenal endocrine hyperactivity and ultimately metabolic disease,” said Dr. Schulman.
Finally, she described small-bowel therapies like endobarrier sleeves, duodenal mucosal resurfacing, and an incisionless anastomosis system designed to improve glycemic control by altering the gut through noninvasive means.
Dr. Schulman has consulted for Apollo Endosurgery, Boston Scientific, Olympus, and MicroTech, and has received research support from GI Dynamics.