Sullivan S, Edmundowicz SA, Thompson CC. Endoscopic Bariatric and Metabolic Therapies: New and Emerging Technologies. Gastroenterol. 2017;152(7):1791-1801. Reference: https://pubmed.ncbi.nlm.nih.gov/27989851/
This review article summarizes the currently available bariatric endoscopic devices and/or procedures as well as the weight loss and safety data from their landmark trials.
Endoscopic bariatric and metabolic therapies (EBMT) are a new addition to the treatment arsenal for obesity. These include devices that are placed or removed via flexible endoscopy, and procedures that utilize instruments that require flexible endoscopy for the indications of weight loss or treatment of glucose intolerance (from pre-diabetes to diabetes). The EBMTs are generally divided into gastric and small bowel categories, and although individual EBMTs may have unique mechanisms of action, similar themes in proposed mechanism of action are seen in the gastric and small bowel EBMTs, respectively. In this review we will describe the therapies approved for use in the United States or currently in the process of obtaining approval for use in the United States. We will discuss potential mechanisms of action and examine safety and efficacy data
Endoscopic bariatric metabolic therapies (EBMT) are devices that require flexible endoscopy for placement or removal and procedures that are performed via flexible endoscopy for the treatment of obesity or glucose intolerance. The category of EBMT encompasses a wide range of device and procedure types that have varying mechanism, resulting in decreased calorie intake. EBMTs produce more weight loss when compared with lifestyle therapy
1, 2 and when compared with weight loss medications. 3 Although no randomized controlled trial of EBMT compared with bariatric surgery has been published to date, weight loss with EBMT is generally less than weight loss reported with bariatric surgery 4; but EBMT has significantly fewer complications, making it an attractive treatment alternative for patients who do not qualify for or do not want bariatric surgery. The following review will discuss the primary EBMTs currently available in the United States or currently under investigation. Details on incorporating these devices into an endoscopy practice is outside of the scope of this review, but further information can be found in medical society position statements.
Gastric Endoscopic Bariatric Metabolic Therapies
The EBMTs that are placed or performed in the stomach vary significantly in their design and mechanisms of action. These include devices that occupy space in the stomach (either with the device or by causing delayed gastric emptying), a device that removes a portion of the calories consumed after a meal (aspiration therapy), and devices that alter gastric anatomy to reduce gastric volume and accommodation (plication and suturing).
Intragastric balloons (IGB) occupy space in the stomach. Research suggests that an IGB volume of at least 400 mL is needed for weight loss. 7 In addition to occupying space in the stomach, some IGBs also alter gastric motility. A randomized controlled trial of the Orbera Intragastric Balloon System (Orbera; Apollo Endosurgery, Austin, TX; Figure 1A) in 27 subjects demonstrated an increase in retained gastric contents 2 hours after radiolabeled meal ingestion in the IGB group compared with the control group 8 weeks after IGB placement (61.4 ± 23.2% and 25.7 ± 18%; P = .0003).8 No difference was seen in retained gastric contents in the IGB group compared with the control group at baseline testing or post-IGB removal testing, supporting the independent role of IGB on gastric motility. Moreover, weight loss was correlated with the change in gastric retention. Gastric hormones involved in hunger, satiety, and control of gastric emptying have also been studied. In two randomized sham controlled studies there was no difference between sham control or active subjects with an IGB on fasting or post-prandial ghrelin concentrations.9, 10 However, fasting and post-prandial cholecystokinin were decreased in active subjects with an IGB compared with controls in a sham controlled study, 11 which may correlate with the delayed gastric emptying seen with IGBs. IGB therapy is also associated with significant weight loss maintenance after removal. Unlike the effect of cessation of weight loss medications where weight lost with the medication is regained within 6 months, 66% to almost 90% of the weight lost with the IGB is maintained 6 months after IGB removal, 1, 12, 13 and may be as high as 50% 18 months after IGB placement. 1