Endoscopic gastroplasty for weight loss: are we finally there?

The current management paradigm for obesity, or better termed adiposity-based chronic disease, focuses on caloric restriction and increased physical activity. However, this approach has insufficiently addressed the disease pathophysiology secondary to a myriad of counter-regulatory physiological responses aimed at defending homeostatic and centrally determined body fat stores by increasing hunger and decreasing energy expenditure [1]. Not surprisingly, when a redundant and evolutionary defended physiological system is disturbed, it will counterbalance the disruption in order to return to equilibrium. Successful interventions for obesity and metabolic disease, such as bariatric and metabolic surgery, disrupt these counter-regulatory responses by targeting peripheral gastric and small intestinal signals that communicate with the central nervous system and other peripheral organs including the liver, pancreas, adipose tissue, and muscle; such interventions result in significant and durable weight loss with resolution of obesity-related metabolic diseases, such as type 2 diabetes mellitus [2].

The low impact and patient acceptance of bariatric surgery, coupled with the limited effectiveness of lifestyle interventions, have propelled the development of multiple endoscopic techniques and devices for the treatment of obesity and metabolic disease. These techniques target similar gastrointestinal pathways to those of bariatric surgery, and have given rise to the field of endobariatrics [3]. Endoscopic gastric remodeling techniques were a strong initial focus of the field. However, earlier efforts were not successful owing to technical limitations of older endoscopic suturing and plication devices, and limited understanding of the effects these gastroplasty techniques have on the gastric neuroenteric circuitry that regulates appetite, gastric emptying, gastric accommodation, and gut neurohormonal response [4]. Earlier gastroplasty procedures were only capable of partially partitioning the stomach to mimic a vertical banded gastroplasty, using either a suction-based superficial suturing device that created an everted mucosa-to-mucosa plication (EndoCinch Suturing System; CR Bard, Murray Hill, New Jersey, USA) or an endoscopic stapling device (TOGA; Satiety Inc, Palo Alto, California, USA) [5].

“Ultimately, selecting the appropriate endoscopic bariatric intervention based on patients’ clinical and physiological determinants of response, coupled with traditional market forces, including device ease of use, cost, and tolerability, will determine its adaptability and success.”

The field of endobariatrics evolved with the development of better full-thickness endoscopic suturing and plication devices that were capable of creating durable serosa-to-serosa apposition and imbricating the greater curvature of the gastric body to create a small-capacity food reservoir in the fundus with a restricted tubular food exit in the gastric body. This remodeled gastric configuration was shown to improve satiation – the amount of food consumed during a meal to reach fullness. The rapid accommodation of the small gastric reservoir in response to the ingested meal activates the afferent vagal and cervical spinal sympathetic nervous system signals to the nucleus tractus solitarii. Furthermore, the procedure increased satiety – the time interval between meals – by delaying gastric emptying and altering the rate by which small intestinal satiety signals are generated and conveyed to the hypothalamus [6].

In this issue of Endoscopy, Huberty et al. report the 12-month safety and weight loss outcomes of transoral anterior-to-posterior greater curvature plications [7]. The method uses an over-the-scope triangulation platform to reduce gastric volume by applying a single interrupted suture anchored by two T-tags (Endomina; EndoTool SA, Gosselies, Belgium). The investigators prospectively performed the study at three European centers. The procedure was performed successfully in 51 patients who had a mean baseline body mass index of 35.1 kg/m² (SD 3). The procedure was performed under general anesthesia in about 97 minutes and required a mean of 5 sutures to complete. All patients were admitted for postoperative observation as per protocol. A total of 30 patients agreed to a repeat upper endoscopy to assess durability of the plications, which appeared durable in 88 % of patients at an interval ranging between 3 and 12 months. Self-limiting post-procedural abdominal pain was reported in most patients; no serious adverse events were, otherwise, reported. Patients followed a low-intensity lifestyle intervention program in the 12 months after the intervention. Percent total body weight loss for 45 patients with 12 months of follow-up was 7.4 % (SD 7), with 51 % of them achieving > 25 % excess weight loss.

Given that most patients with mild-to-moderate obesity are unable to reach significant weight loss with lifestyle interventions alone, nor qualify for bariatric surgery, gastroplasty techniques, such as the one described by Huberty et al. will continue to evolve to fill this management gap. Despite an excellent safety profile, in its current form, this procedure resulted in weight loss similar to that achieved by obesity pharmacotherapies and intragastric balloons, was performed under general anesthesia, and required relatively longer procedure times compared with other endoscopic interventions. Nevertheless, the sutured plications appeared to be durable and, compared with gastric balloons, the procedure was better tolerated and only required one endoscopy session. Ultimately, selecting the appropriate endoscopic bariatric intervention based on patients’ clinical and physiological determinants of response, coupled with traditional market forces, including device ease of use, cost, and tolerability, will determine its adaptability and success. Until then, we need to continue to expand our obesity treatment armamentarium with safe and effective tools to battle this adiposity-based chronic disease.

• References

• 1 Sumithran P, Prendergast LA, Delbridge E. et al. Long-term persistence of hormonal adaptations to weight loss. N Engl J Med 2011; 365: 1597-1604
• 2 Schauer PR, Bhatt DL, Kirwan JP. et al. Bariatric surgery versus intensive medical therapy for diabetes – 5-year outcomes. N Engl J Med 2017; 376: 641-651
• 3 Storm AC, Abu Dayyeh BK, Topazian M. Endobariatrics: a primer. Clin Gastroenterol Hepatol 2018; DOI: 10.1016/j.cgh.2018.03.009.
• 4 Cummings DE, Overduin J. Gastrointestinal regulation of food intake. J Clin Invest 2007; 117: 13-23
• 5 Abu Dayyeh BK. The hunger games: lessons from the past to shape the future. Gastrointest Endosc 2017; 85: 838-840
• 6 Abu Dayyeh BK, Acosta A, Camilleri M. et al. Endoscopic sleeve gastroplasty alters gastric physiology and induces loss of body weight in obese individuals. Clin Gastroenterol Hepatol 2017; 15: 37-43
• 7 Huberty V, Machytka E, Boškoski I. et al. Endoscopic gastric reduction with an endoluminal-suturing device: a multicenter prospective trial with 1-year follow-up. Endoscopy 2018; 50: 1156-1162