Gastric mucosal devitalization (GMD): translation to a novel endoscopic metabolic therapy

Endoluminal bariatric and metabolic therapies: state-of-the-art

PURPOSE OF REVIEW

The aim of this review is to present the current state of the field, highlight recent developments, and describe the clinical outcomes of these endoluminal bariatric and metabolic procedures.

RECENT FINDINGS

The landscape of endoluminal devices and techniques for treating obesity has expanded significantly, with FDA-approved therapies currently available to patients with a body mass index values as high as 50 kg/m2. Although notable advancements have been made in this area, there is a need for further emphasis to be placed on the metabolic improvements resulting from these therapies, in addition to the conventional focus on weight loss outcomes. Some of these procedures are now FDA approved for the treatment of metabolic disease as opposed to weight loss. To achieve the most favorable results, it is imperative that all endoluminal interventions are combined with a moderately intensive diet and lifestyle program lasting at least 12 months.

SUMMARY

Endoluminal metabolic and bariatric therapy represents a bridge between lifestyle counseling, pharmaceutical interventions, and the most efficacious treatment for obesity, bariatric surgery. By virtue of its minimally invasive approach, this therapy may be an appealing option for patients who are ineligible for, or averse to, bariatric surgery and who have experienced suboptimal outcomes or unable to afford medical treatments. Furthermore, these interventions may be particularly beneficial in the early stages of obesity.

Updates in Endoscopic Bariatric and Metabolic Therapies

The rising prevalence of obesity, and related morbidity and mortality, has necessitated the development of therapeutic weight loss strategies. Lifestyle modifications alone have only yielded modest benefit, and while bariatric surgery has shown significant short- and long-term results, only a minority of eligible patients end up receiving this treatment. Endoscopic bariatric and metabolic therapies (EBMTs) are a rapidly evolving field, which provides a less invasive middle ground treatment option for weight loss. Here we discuss the efficacy, as well as short- and long-term outcomes with restrictive, malabsorptive/metabolic and aspiration endoscopic techniques, and their effects on metabolic parameters.

Gastric Mucosal Devitalization (GMD): Using the Porcine Model to Develop a Novel Endoscopic Bariatric Approach

BACKGROUND AND AIMS

As the pig model has similar gastrointestinal anatomy and physiology to humans, we used pigs to create a gastric mucosal devitalization (GMD) model in preparation for clinical translation of this technique as an endoscopic bariatric therapy (EBT). The aims of this study were to determine the ablation parameters and technique for a successful, safe, and feasible large surface area GMD that produces weight loss.

METHODS

We performed GMD using argon plasma coagulation (APC) in 3 phases. Phase 1 assessed the ablation energy required to accomplish selective mucosal ablation using ex vivo pig stomachs (n = 2). Phase 2 assessed the optimal percentage of mucosal surface area to be treated and was performed on 10 pigs. Phase 3 assessed feasibility, efficacy, and safety with 8 pigs randomized into GMD (n = 4) or sham (SH, n = 4) and survived for 1 month. Body weights (GMD, n = 4, SH, n = 4) were measured daily in phase 3 for 1 month, and relative body weights were calculated and analyzed using one-tailed Student's t-test. Percent body fat was compared between GMD and SH at baseline and 1 month post-GMD.

RESULTS

Phase 1 identified the optimal ablation parameters (120 W) that were then used in phase 2. Phase 2 revealed a trend that was suggestive that the optimal percent surface area to ablate was similar to that which is removed at laparoscopic sleeve gastrectomy. In phase 3, GMD was performed over 70% surface area of the greater curvature of the stomach in four pigs. GMD pigs had significantly lower relative body weight increase compared to SH at 1 month (1.375 ± 0.085 vs 1.575 ± 0.047, p = 0.0435). MRI showed a significantly lower body fat mass at 1 month in GMD pigs (5.9 ± 0.4% vs 12.7 ± 2.3%, p = 0.026) compared to SH.

CONCLUSIONS

GMD resulted in decreased weight gain in the GMD group as evidenced by a lower relative body weight at 1 month. GMD in an animal model appears to show promise as a potential weight loss therapy.

Endobariatrics and Metabolic Endoscopy: Can We Solve the Obesity Epidemic with Our Scope?

PURPOSE OF REVIEW

Obesity is a chronic relapsing disease that results in cardiovascular disease, diabetes mellitus, and non-alcoholic fatty liver disease. Currently, surgery represents the most effective treatment. However, the advent of minimally invasive endoscopic bariatric therapy (EBT) has shifted the treatment paradigm to less invasive, cost-effective procedures with minimal complications and recovery time that are preferred by patients. In this review, we will describe current and future EBTs, focusing on outcomes and safety.

RECENT FINDINGS

The endoscope has provided an incisionless portal into the gastrointestinal tract for placement of space-occupying devices and intraluminal procedures. EBTs are no longer solely manipulating anatomic alterations; instead, they aim to improve metabolic parameters such as glycated hemoglobin, low-density lipoprotein, cholesterol, and hepatic indices by targeting the mucosal layer of the gastrointestinal tract. The endoscope has succeeded in facilitating clinically meaningful weight loss and improvement of metabolic parameters. Future, solutions to the obesity epidemic will likely entail genetic testing, evaluation of the microbiome, and delivery of personalized therapy, utilizing combination endoscopic modalities that change the anatomy and physiology of individual patients, with new targets such as the abnormal metabolic signal.