Effect of Endoscopic Sleeve Gastroplasty in Patients With Obesity and MASH: A Randomized Controlled Trial

The National Institutes of Health, the World Health Organization, and numerous other scientific organizations including the America Medical Association (AMA) recognize obesity as a chronic disease requiring primary therapy. Almost half of United States (U.S.) adults have obesity. The increasing prevalence of obesity in the U.S. has been accompanied by an increasing prevalence in its associated comorbid conditions including hypertension, diabetes, dyslipidemia, coronary heart disease, stroke, sleep apnea, osteoarthritis, gallbladder disease, GERD, and metabolic dysfunction-associated steatotic liver disease (MASLD)/metabolic dysfunction-associated steatohepatitis (MASH). Obesity is associated with an increased risk of all-cause and cardiovascular mortality and accounts for about 2.5 million preventable deaths annually. The economic consequences of MASH are enormous, with the lifetime cost of care for all patients with MASH projected to be approximately $222 billion as of 2017.

Current treatment options for patients with MASLD/MASH are limited to weight loss via lifestyle modification and more recently, Food and Drug Administration (FDA)-approved medications, such as resmetirom and semaglutide, indicated specifically for patients with MASH and F2-F3 fibrosis. Nevertheless, less than 10% of patients who undergo lifestyle modification experience at least 10% total weight loss (TWL), the threshold required for hepatic fibrosis regression. The available pharmacological approaches for the treatment of obesity increase weight loss by 3% to 9% compared with lifestyle therapy alone, but some can be associated with unfavorable side effects, significant cost, and weight loss achieved by pharmacotherapy is rarely maintained upon withdrawal of the medication. On the other end of the spectrum, bariatric surgery, such as Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy, has shown promise in the treatment of MASLD/MASH due to its ability to induce significant and durable weight loss of at least 10% TWL. Nevertheless, its adoption has been limited with less than 2% of patients eligible for the surgery choosing to undergo the procedure. This is likely due to the perceived invasiveness of surgery, high costs, and limited access. More importantly, the majority of patients with mild to moderate (class I and class II obesity (BMI 30-40 kg/m2)), who do not qualify for bariatric surgery are left without an effective management, considering the modest effects seen with medications or lifestyle intervention alone and their ability to achieve >10%TWL only in the minority of patients. Yet, according to the global disability-adjusted life-years and deaths study, patients with mild to moderate obesity are the highest contributors to the burden on disease both in terms of co-morbidities and overall mortality. Therefore, both government agencies (the Agency for Healthcare Research and Quality [AHRQ]) and national societies (American Society of Bariatric and Metabolic Surgery [ASMBS], and American Society of Gastrointestinal Endoscopy [ASGE]) now recognize that a significant management gap exists for patients with mild to moderate obesity and have defined safety and efficacy thresholds for adoption of a new treatment category- endoscopic weight loss interventions.

Over the past decades, endoscopic bariatric and metabolic therapies (EBMTs) have been developed to fill the treatment gap for obesity and MASLD/MASH. Specifically, compared to lifestyle modification, EBMTs are associated with greater weight loss with a higher proportion of patients reaching the 10% TWL threshold. Additionally, given its non-surgical, minimally-invasive nature, the safety profile for EBMTs appears more favorable compared to bariatric surgery. To date, there are two EBMT devices and/or procedures that are approved or cleared by the Food and Drug Administration (FDA). These include intragastric balloons (IGBs) and endoscopic sleeve gastroplasty (ESG).

The ESG procedure is an endoscopic minimally-invasive weight loss procedure where a commercially available, FDA-approved, full-thickness endoscopic suturing device (Overstitch; Boston Scientific, Marlborough, MA) is used to reduce the stomach volume by 70% through the creation of a restrictive endoscopic sleeve. This is accomplished by a series of endoluminally placed full-thickness stitches through the gastric wall, extending from the distal gastric body to the proximal gastric body. The investigators currently perform this procedure as a standard of care at Brigham and Women's Hospital (BWH). Our previous studies have demonstrated that ESG not only leads to significant weight loss of at least 10% TWL, but also improves non-invasive tests (NITs) of liver steatosis and fibrosis, as well as MASH histologic features in patients with obesity and concomitant MASH. Nevertheless, it remains unclear if ESG is superior to lifestyle modification alone.

Clinical Data to Date

The feasibility of ESG was first demonstrated in humans in the US in 2013. Since then, the technique has gained wide clinical adoption in the US and worldwide with thousands of cases performed. Multiple single-arm prospective and retrospective studies have demonstrated the safety and minimally invasive nature of the technique and reported %TWL of about 16% to 18% at 12 months. Furthermore, studies have demonstrated physiologic perturbations resulting from creation of the ESG and its association with increased satiation and metabolic effects that are potentially important to control the metabolic dysregulation associated with obesity. In a recent randomized controlled trial including 209 participants, subjects were randomized to either ESG combined with lifestyle modification (n=85) or lifestyle modification alone (n=124). At 12 months, the ESG group achieved significantly greater weight loss of 13.6% TWL, compared to 0.8% in the control group. ESG-related serious adverse events occurred in only 2% of participants, with no instances of mortality, intensive care, or surgery required. While ESG has demonstrated both safety and efficacy for weight loss, no RCTs have yet assessed its impact on obesity-related comorbidities.