Short-term safety and efficacy of the Trans-oral Endoscopic Restrictive Implant System for the treatment of obesity

Efficacy and Mechanisms of Gastric Volume-Restriction Bariatric Devices

Obesity is a chronic disease that affects over 795 million people worldwide. Bariatric surgery is an effective therapy to combat the epidemic of clinically severe obesity, but it is only performed in a very small proportion of patients because of the limited surgical indications, the irreversibility of the procedure, and the potential postoperative complications. As an alternative to bariatric surgery, numerous medical devices have been developed for the treatment of morbid obesity and obesity-related disorders. Most devices target restriction of the stomach, but the mechanism of action is likely more than just mechanical restriction. The objective of this review is to integrate the underlying mechanisms of gastric restrictive bariatric devices in obesity and comorbidities. We call attention to the need for future studies on potential mechanisms to shed light on how current gastric volume-restriction bariatric devices function and how future devices and treatments can be further improved to combat the epidemic of obesity.

Upper Gastrointestinal Function in Morbidly Obese Adolescents Before and 6 Months After Gastric Banding

BACKGROUND

The effects of laparoscopic adjustable gastric band (LAGB) placement on upper gastrointestinal tract function in obese adolescents are unknown. Therefore, our aim was to determine the short-term effects of LAGB on esophageal motility, gastroesophageal reflux, gastric emptying, appetite-regulatory hormones, and perceptions of post-prandial hunger and fullness.

METHODS

This study was part of a prospective cohort study (March 2009-December 2015) in one tertiary referral hospital. The study included obese adolescents (14-18 years) with a body mass index (BMI) > 40 (or ≥ 35 with comorbidities). Gastric emptying was assessed by ¹³C-octanoic acid breath test, pharyngeal, and esophageal motor function by high-resolution manometry with impedance (HRIM), and appetite and other perceptions using 100-mm visual analogue scales. Dysphagia symptoms were scored using a Dakkak questionnaire. Data were compared pre- and post-LAGB placement and at a 6-month follow-up.

RESULTS

Based upon analysis of 15 adolescents, at the 6-month follow-up, LAGB placement: (i) led to a significant reduction in weight and BMI; (ii) increased fullness and decreased hunger post-meal; (iii) increased symptoms of dysphagia after solid food; and, despite these effects, (iv) caused little or no changes to appetite hormones, while (v) effects on gastric emptying, esophageal motility, esophageal bolus transport, and esophageal emptying were not significant.

CONCLUSION

In adolescents, LAGB improved BMI and altered the sensitivity to nutrients without significant effects on upper gastrointestinal tract physiology at the 6-month follow-up.

Development of Bariatric and Metabolic Endoscopy

Objective:

With the evolution of society and changes in human lifestyle, obesity is becoming increasingly prevalent worldwide, and obesity-related comorbidities such as diabetes, hyperlipidemia, hypertension, and coronary heart disease are more common. As a result, new devices and methods for bariatric and metabolic endoscopy are being developed for clinical use, offering new options for patients. This review discussed the progress in bariatric and metabolic endoscopy.

Data Sources:

This review was based on data in articles published in the PubMed database up to September 2017, with the following keywords: “obesity”, “endoscopy”, “weight loss”, and “metabolism”.

Study Selection:

Original articles about various endoscopic methods of weight loss and other reviews of bariatric and metabolic endoscopy were included and analyzed.

Results:

The technology of bariatric and metabolic endoscopy has advanced rapidly in recent years. The intragastric balloon (IGB), with its comparatively long period of development, is the most mature and widely used instrument. Multiple new endoscopic devices have been created in recent years, with different targets to achieve weight loss. Despite the proliferation of new devices, the lack of clinical data results in a shortage of clinical experience and instruction in the use of this new equipment.

Conclusions:

Bariatric and metabolic endoscopy would help obese people lose weight or prepare for bariatric surgery and hopefully alleviate some of the complications of bariatric procedures. Adequate studies and data are still needed for the new endoscopic devices.

Endoluminal weight loss and metabolic therapies: current and future techniques

Obesity is a public health epidemic associated with a number of comorbidities, most notably type 2 diabetes and hypertension, as well as elevated all-cause mortality. The treatment for obesity and its associated comorbidities has most recently expanded into the field of bariatric endoscopy. This field bridges a gap between lifestyle counseling with or without pharmaceutical treatment and the most effective treatment of obesity, bariatric surgery. Because of its minimally invasive nature, bariatric endoscopic therapy has the potential to appeal to the large sector of the obese population that resists surgery, as well as those early in the onset of obesity. To date, five endoscopic devices have been approved by the U.S. Food and Drug Administration for the treatment of obesity, and many more are in development, undergoing clinical trials, or being used around the world. Here, we present the current state of the field, highlight recent developments, and describe the clinical outcomes of these minimally invasive procedures in terms of weight loss, improvement in metabolic profile, and reduction in comorbidities.

Endoscopic Bariatric and Metabolic Therapies: Surgical Analogues and Mechanisms of Action

Obesity is a worsening pandemic with numerous related comorbid illnesses. Conservative management including lifestyle modification and medications have limited efficacy. In contradistinction, bariatric surgery is effective, however, with substantial cost and non-negligible morbidity and mortality. As such, a small percentage of eligible patients undergo surgery. Over the past decade, endoscopic bariatric and metabolic therapies have been introduced as a less invasive option for the treatment of obesity and its related comorbid illnesses. This article reviews major endoscopic bariatric and metabolic therapies, their surgical analogues, and proposed mechanisms of action. Clinical trial data for each device also are discussed.

Selected Endoscopic Gastric Devices for Obesity

This article focuses on the stomach target devices that are currently in various stages of development. Approved intragastric balloons, devices targeting small bowel and aspiration techniques, are described in other contributions to this issue. Bariatric endoscopic devices targeting the stomach directly alter gastric physiology and promote weight loss by potentially changing functional gastric volume, gastric emptying, gastric wall compliance, neurohormonal signaling, and, thereby, satiety. Many stomach-targeting devices are on the horizon for clinical use, and further study will determine the safety and efficacy for clinical use.

Innovative solutions in bariatric surgery

Nowadays all over the world the rising plague of obesity can be observed. The obesity was recognized as "an epidemic of XXI century" in 1997 by World Health Organization. The change of eating habits, active lifestyle or pharmacological curation are often insufficient to fight against obesity. Nowadays, there are not any guidelines about gold standard for curing obese patients is bariatric surgery. At the moment, two types of bariatric procedures: laparoscopic Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy, are most commonly used. There are also some other new approaches, which are still being investigated. The mechanism of losing weight in bariatric surgery is based on restriction, malabsorption and neurohormonal effect. Not only is the surgery technique very important to succeed, but also the postoperative care in the outpatient clinic. This article reviews the new possibilities in obesity treatment.

Recent Trends in Endoscopic Management of Obesity

Obesity remains a tremendous public health, clinical, and scientific challenge globally. Conventional approaches in the management of obesity offer limited potential for sustained weight loss. Bariatric surgery, although it represents the most effective weight loss treatment, has its own risks and is associated with substantial costs and limited patient applicability. Endoscopic weight loss procedures are considered as the major breakthrough in the management of obesity. Endoluminal interventions performed entirely through the gastrointestinal tract have evolved as a result of an attempt to replicate some of the anatomical features and the physiological effects of the traditional weight loss surgery while being reversible, less invasive, and more cost-effective. Restrictive procedures act to decrease gastric volume by space-occupying devices and/or by suturing or stapling techniques that alter gastric anatomy, whereas malabsorptive procedures tend to create malabsorption by preventing food contact with the duodenum and proximal jejunum. Other procedures act by influencing gastric function (gastric botulinum injections, gastric pacing, and vagal nerve blocking) or by gastric aspiration. It is important to underline that the majority of endoscopic weight loss procedures are still being evaluated and are not yet available routinely. Even though some of the techniques and devices that have recently emerged have demonstrated promising short-term results, evidence on their safety and long-term efficacy from well-designed and well-conducted research should be given before they can become an inherent part of everyday clinical practice. Given the rapid development of endoscopic weight loss procedures, this review considers the current state and recent trends in endoscopic management of obesity.

Endoscopic Devices for Obesity

The obesity epidemic, recognized by the World Health Organization in 1997, refers to the rising incidence of obesity worldwide. Lifestyle modification and pharmacotherapy are often ineffective long-term solutions; bariatric surgery remains the gold standard for long-term obesity weight loss. Despite the reported benefits, it has been estimated that only 1% of obese patients will undergo surgery. Endoscopic treatment for obesity represents a potential cost-effective, accessible, minimally invasive procedure that can function as a bridge or alternative intervention to bariatric surgery. We review the current endoscopic bariatric devices including space occupying devices, endoscopic gastroplasty, aspiration technology, post-bariatric surgery endoscopic revision, and obesity-related NOTES procedures. Given the diverse devices already FDA approved and in development, we discuss the future directions of endoscopic therapies for obesity.

Novel Endoscopic Management of Obesity

Endoscopic procedures have been well-documented in the obesity field, but have not yet reached a sufficient level of evidence as stand-alone methods for treating obesity. It is unclear if they should take over. Although expanding, the array of bariatric surgical techniques does not fully meet the current needs, and there are not enough resources for increasing surgery. Surgery is avoided by a majority of patients, so that less aggressive procedures are necessary. For the time being, relevant endoscopic methods include intra-gastric balloons, gastric partitioning (Endo-plication), and the metabolic field (Endo-barrier). Surgical novelties and basic research are also important contributors owing to their potential combination with endoscopy. Conditions have been listed for implementation of bariatric endoscopy, because innovation is risky, expensive, and faces ethical challenges. A scientific background is being built (e.g., hormonal studies). Some techniques require additional study, while others are not ready but should be priorities. Steps and goals include the search for conceptual similarities and the respect of an ethical frame. Minimally invasive bariatric techniques are not ready for prime time, but they are already being successful as re-do procedures. A time-frame for step-strategies can be defined, and more investments from the industry are mandatory.

Endoscopic therapy for weight loss: Gastroplasty, duodenal sleeves, intragastric balloons, and aspiration

A new paradigm in the treatment of obesity and metabolic disease is developing. The global obesity epidemic continues to expand despite the availability of diet and lifestyle counseling, pharmacologic therapy, and weight loss surgery. Endoscopic procedures have the potential to bridge the gap between medical therapy and surgery. Current primary endoscopic bariatric therapies can be classified as restrictive, bypass, space-occupying, or aspiration therapy. Restrictive procedures include the USGI Primary Obesity Surgery Endolumenal procedure, endoscopic sleeve gastroplasty using Apollo OverStitch, TransOral GAstroplasty, gastric volume reduction using the ACE stapler, and insertion of the TERIS restrictive device. Intestinal bypass has been reported using the EndoBarrier duodenal-jejunal bypass liner. A number of space-occupying devices have been studied or are in use, including intragastric balloons (Orbera, Reshape Duo, Heliosphere BAG, Obalon), Transpyloric Shuttle, and SatiSphere. The AspireAssist aspiration system has demonstrated efficacy. Finally, endoscopic revision of gastric bypass to address weight regain has been studied using Apollo OverStitch, the USGI Incisionless Operating Platform Revision Obesity Surgery Endolumenal procedure, Stomaphyx, and endoscopic sclerotherapy. Endoscopic therapies for weight loss are potentially reversible, repeatable, less invasive, and lower cost than various medical and surgical alternatives. Given the variety of devices under development, in clinical trials, and currently in use, patients will have multiple endoscopic options with greater efficacy than medical therapy, and with lower invasiveness and greater accessibility than surgery.

Endoscopic gastric volume reduction with a novel articulating plication device is safe and effective in the treatment of obesity (with video)

BACKGROUND

Endoscopic volume reduction of the stomach may provide a minimally invasive alternative for surgical procedures in the treatment of obesity.

OBJECTIVE

To assess safety and preliminary effectiveness in the first human application of a novel endoscopic stapling technique.

DESIGN

Prospective, observational, phase 1 study.

SETTING

Two university hospitals in The Netherlands.

PATIENTS

Patients with a body mass index (BMI) of 40 to 45 kg/m(2) or 30 to 39.9 kg/m(2) with obesity-related comorbidity.

INTERVENTIONS

Gastric volume reduction with an endoscopic stapler.

MAIN OUTCOME MEASUREMENTS

Primary outcome measure was the prevalence of serious or mild adverse events. Reduction of excess body weight after 12 months was assessed as a secondary outcome measure for effectiveness of the procedure.

RESULTS

Seventeen patients with a median BMI of 40.2 kg/m(2) (interquartile range [IQR] 37.6-42.8) underwent an endoscopic stapling procedure. Median procedure time was 123 minutes (IQR 95-129). No serious adverse events occurred. Adverse events were gastric pain (n = 7, range 1-3 days), sore throat (n = 4, 2-3 days), diarrhea (n = 4, 2-15 days), nausea (n = 3, 2-4 days), constipation (n = 4, 3-14 days), and vomiting (n = 3, 1-4 days). All adverse events were mild and resolved with conservative treatment within 15 days after surgery. The median percentage excess weight loss in the first year was 34.9% (IQR 17.8-46.6).

LIMITATIONS

Limited number of patients.

CONCLUSION

This first human application of this endoscopic stapler demonstrates that the procedure is technically feasible and safe. One hundred sixty plications were created in 17 patients without significant problems. Weight loss after 1 year is promising, but long-term follow-up and randomized, controlled studies should evaluate whether this procedure is an effective and durable minimally invasive endoscopic treatment for obesity. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01429194.).

Development of minimally invasive techniques for management of medically-complicated obesity

The field of bariatric surgery has been rapidly growing and evolving over the past several decades. During the period that obesity has become a worldwide epidemic, new interventions have been developed to combat this complex disorder. The development of new laparoscopic and minimally invasive treatments for medically-complicated obesity has made it essential that gastrointestinal physicians obtain a thorough understanding of past developments and possible future directions in bariatrics. New laparoscopic advancements provide patients and practitioners with a variety of options that have an improved safety profile and better efficacy without open, invasive surgery. The mechanisms of weight loss after bariatric surgery are complex and may in part be related to altered release of regulatory peptide hormones from the gut. Endoscopic techniques designed to mimic the effects of bariatric surgery and endolumenal interventions performed entirely through the gastrointestinal tract offer potential advantages. Several of these new techniques have demonstrated promising, preliminary results. We outline herein historical and current trends in the development of bariatric surgery and its transition to safer and more minimally invasive procedures designed to induce weight loss.

Endoscopic treatment: the past, the present and the future

The obesity epidemic asks for an active involvement of gastroenterologists: many of the co-morbidities associated with obesity involve the gastrointestinal tract; a small proportion of obese patients will need bariatric surgery and may suffer from surgical complications that may be solved by minimally invasive endoscopic techniques; and finally, the majority will not be eligible for bariatric surgery and will need some other form of treatment. The first approach should consist of an energy-restricted diet, physical exercise and behaviour modification, followed by pharmacotherapy. For patients who do not respond to medical therapy but are not or not yet surgical candidates, an endoscopic treatment might look attractive. So, endoscopic bariatric therapy has a role to play either as an alternative or adjunct to medical treatment. The different endoscopic modalities may vary in mechanisms of action: by gastric distension and space occupation, delayed gastric emptying, gastric restriction and decreased distensibility, impaired gastric accommodation, stimulation of antroduodenal receptors, or by duodenal exclusion and malabsorption. These treatments will be discussed into detail.

Early experience with the Incisionless Operating Platform™ (IOP) for the treatment of obesity : the Primary Obesity Surgery Endolumenal (POSE) procedure

BACKGROUND

We report our initial experience and 6-month outcomes in a single center using the per-oral Incisionless Operating Platform™ (IOP) (USGI Medical) to place transmural plications in the gastric fundus and distal body using specialized suture anchors (the Primary Obesity Surgery Endolumenal [POSE] procedure).

METHODS

A prospective observational study was undertaken with institutional Ethics Board approval in a private hospital in Barcelona, Spain. Indicated patients were WHO obesity class I-II, or III, where patients refused a surgical approach.

RESULTS

Between February 28, 2011 and March 23, 2012, the POSE procedure was successfully performed in 45 patients: 75.6 % female; mean age 43.4 ± 9.2 SD (range 21.0-64.0). At baseline: mean absolute weight (AW, kg), 100.8 ± 12.9 (75.5-132.5); body mass index (BMI, kg/m(2)), 36.7 ± 3.8 (28.1-46.6). A mean 8.2 suture-anchor plications were placed in the fundus, 3.0 along the distal body wall. Mean operative time, 69.2 ± 26.6 min (32.0-126.0); patients were discharged in <24 h. Six-month mean AW was 87.0 ± 10.3 (68.0-111.5); BMI decreased 5.8 to 31.3 ± 3.3 (25.1-38.6) (p < 0.001); EWL was 49.4 %; TBWL, 15.5 %. No mortality or operative morbidity. Minor postoperative side effects resolved with treatment by discharge. Patients reported less hunger and earlier satiety post procedure. Liquid intake began 12 h post procedure with full solids by 6 weeks.

CONCLUSIONS

At 6-month follow-up of a prospective case series, the POSE procedure appeared to provide safe and effective weight loss without the scarring, pain, and recovery issues of open and laparoscopic bariatric surgery. Long-term follow-up and further study are required.

Early experience with the Incisionless Operating Platform™ (IOP) for the treatment of obesity : the Primary Obesity Surgery Endolumenal (POSE) procedure

BACKGROUND

We report our initial experience and 6-month outcomes in a single center using the per-oral Incisionless Operating Platform™ (IOP) (USGI Medical) to place transmural plications in the gastric fundus and distal body using specialized suture anchors (the Primary Obesity Surgery Endolumenal [POSE] procedure).

METHODS

A prospective observational study was undertaken with institutional Ethics Board approval in a private hospital in Barcelona, Spain. Indicated patients were WHO obesity class I-II, or III, where patients refused a surgical approach.

RESULTS

Between February 28, 2011 and March 23, 2012, the POSE procedure was successfully performed in 45 patients: 75.6 % female; mean age 43.4 ± 9.2 SD (range 21.0-64.0). At baseline: mean absolute weight (AW, kg), 100.8 ± 12.9 (75.5-132.5); body mass index (BMI, kg/m(2)), 36.7 ± 3.8 (28.1-46.6). A mean 8.2 suture-anchor plications were placed in the fundus, 3.0 along the distal body wall. Mean operative time, 69.2 ± 26.6 min (32.0-126.0); patients were discharged in <24 h. Six-month mean AW was 87.0 ± 10.3 (68.0-111.5); BMI decreased 5.8 to 31.3 ± 3.3 (25.1-38.6) (p < 0.001); EWL was 49.4 %; TBWL, 15.5 %. No mortality or operative morbidity. Minor postoperative side effects resolved with treatment by discharge. Patients reported less hunger and earlier satiety post procedure. Liquid intake began 12 h post procedure with full solids by 6 weeks.

CONCLUSIONS

At 6-month follow-up of a prospective case series, the POSE procedure appeared to provide safe and effective weight loss without the scarring, pain, and recovery issues of open and laparoscopic bariatric surgery. Long-term follow-up and further study are required.

[Intraluminal/endoscopic procedures in the treatment of obesity]

Few effective therapeutic tools are currently available to fight the increasing prevalence of obesity and its associated comorbidities. Bariatric surgery is the only treatment with proven long-term effectiveness, but is associated to a high surgical risk and significant economic costs because of its technical complexity and the characteristics of patients. This is leading to development of new endoscopic procedures with less clinical risks and economic costs, while maintaining the benefits in terms of morbidity and mortality, which could even serve as a bridging element before surgery in cases where this is unavoidable, allowing for preoperative weight loss and control of comorbidities in order to improve anesthetic risks and possible complications. The purpose of this review was to analyze the most relevant and promising endoscopic techniques currently available.

Endoscopic sleeve gastroplasty: a potential endoscopic alternative to surgical sleeve gastrectomy for treatment of obesity

BACKGROUND

Obesity and its associated conditions, including type 2 diabetes and cardiovascular disease, have reached epidemic proportions. High-efficacy, high-risk surgical approaches are unlikely to meet the increasing burden of disease. Emerging endoscopic technologies have opened the door for endoscopic approaches to reproduce many of the benefits of GI weight loss surgery and thereby contribute to the effective treatment of obesity and its associated disorders.

OBJECTIVE

To demonstrate the technical feasibility of transoral endoscopic gastric volume reduction with an endoscopic suturing device in a fashion similar to sleeve gastrectomy for the treatment of obesity.

DESIGN

Single-center, pilot feasibility study.

PATIENTS

Four human subjects with obesity.

INTERVENTIONS

Transoral sleeve gastroplasty.

MAIN OUTCOME MEASUREMENTS

Technical feasibility.

RESULTS

We successfully used an endoscopic free-hand suturing system in 4 subjects, thus demonstrating the technical feasibility of a novel technique to mimic the anatomic manipulations created by surgical sleeve gastrectomy endoscopically.

LIMITATIONS

Pilot feasibility study with small number of subjects.

CONCLUSIONS

Endoscopic sleeve gastroplasty for treatment of obesity is feasible.

The role of endoscopy in bariatrics: past, present, and future

The exponential increase in the rate of obesity and its associated co-morbidities has increased the demand for bariatric surgery. Over the past few decades, surgical weight reduction by gastric restriction, malabsorption, or a combination of both has been the preferred approach to achieve sustained weight loss in the morbidly obese. Although extremely effective, surgical procedures carry significant complications and risk with mortality rates of 1%. Because of the cost, surgical risk, and complications, there is a demand for less invasive procedures. Endoscopic approaches include placement of endoluminal space-occupying devices, stapling devices to reduce gastric volume, barrier devices to reduce small bowel absorptive area, and methods to regulate gastric emptying. Current and ongoing studies have delivered promising results across many aspects of endoscopic approaches. However, many technical obstacles still exist that have to be resolved with further research before endoscopic bariatrics can be widely deployed. At present the role of endoscopy is well established in preoperative evaluation as well as in recognition and management of many postoperative complications in bariatrics. In this article, we review the current and future endoscopic methods for weight reduction that are either in practice or in testing.

Gastric electrical stimulation for the treatment of obesity: from entrainment to bezoars-a functional review

GROWING WORLDWIDE OBESITY EPIDEMIC HAS PROMPTED THE DEVELOPMENT OF TWO MAIN TREATMENT STREAMS: (a) conservative approaches and (b) invasive techniques. However, only invasive surgical methods have delivered significant and sustainable benefits. Therefore, contemporary research exploration has focused on the development of minimally invasive gastric manipulation methods featuring a safe but reliable and long-term sustainable weight loss effect similar to the one delivered by bariatric surgeries. This antiobesity approach is based on placing external devices in the stomach ranging from electrodes for gastric electrical stimulation to temporary intraluminal bezoars for gastric volume displacement for a predetermined amount of time. The present paper examines the evolution of these techniques from invasively implantable units to completely noninvasive patient-controllable implements, from a functional, rather than from the traditional, parametric point of view. Comparative discussion over the available pilot and clinical studies related to gastric electrical stimulation outlines the promises and the fallacies of this concept as a reliable alternative anti-obesity strategy.

Endoluminal bariatric techniques

The American Society for Gastrointestinal Endoscopy (ASGE) Technology Committee provides reviews of new or emerging endoscopic technologies that have the potential to have an impact on the practice of GI endoscopy. Evidence-based methodology is used, with a MEDLINE literature search to identify pertinent preclinical and clinical studies on the topic and a MAUDE (U.S. Food and Drug Administration Center for Devices and Radiological Health) database search to identify the reported complications of a given technology. Both are supplemented by accessing the "related articles" feature of PubMed and by scrutinizing pertinent references cited by the identified studies. Controlled clinical trials are emphasized, but in many cases, data from randomized, controlled trials are lacking. In such cases, large case series, preliminary clinical studies, and expert opinions are used. Technical data are gathered from traditional and Web-based publications, proprietary publications, and informal communications with pertinent vendors. For this review, the MEDLINE database was searched through January 2011 using the keywords "bariatric," "endoscopic," "intragastric balloon," "duodenojejunal bypass sleeve," and "transoral gastroplasty." Reports on Emerging Technologies are drafted by 1 or 2 members of the ASGE Technology Committee, reviewed and edited by the committee as a whole, and approved by the Governing Board of the ASGE. These reports are scientific reviews provided solely for educational and informational purposes. Reports on Emerging Technologies are not rules and should not be construed as establishing a legal standard of care or as encouraging, advocating, requiring, or discouraging any particular treatment or payment for such treatment.

Endoscopic approaches to obesity

Given the emerging role of endoscopic procedures in the treatment of obesity and rapid changes in endoscopic technologies and techniques, this review considers the current state of endoscopic management of obesity. Endoluminal interventions performed entirely through the GI tract by using flexible endoscopy offer the potential for an ambulatory weight loss procedure that may be safer and more cost- effective compared with current surgical approaches. Endoscopic techniques attempt to mimic the anatomic features of bariatric surgery. Accordingly, there are two main endoscopic weight loss modalities - restrictive and malabsorptive. Restrictive procedures act to decrease gastric volume by space-occupying prosthesis and/or by suturing or stapling devices, while malabsorptive procedures tend to create malabsorption by preventing food contact with the duodenum and proximal jejunum. The former include intragastric balloon treatment, endoluminal vertical gastroplasty, transoral gastroplasty and transoral endoscopic restrictive implant system, while the latter include duodenojejunal bypass sleeve. Gastroduodenojejunal bypass sleeve is a combination of both procedures. Except for intragastric balloon, all mentioned procedures are rather new, tested on a small number of human subjects, with a high rate of success, but with limited knowledge on safety and long-term efficacy. The role of gastric electrical stimulation and intragastric injections of botulinum toxin in obesity treatment is also considered as is the role of minimally invasive bariatric endoscopic interventions.

Future directions in bariatric surgery

Bariatric surgery is a field in rapid evolution, and the speed of this evolution has been accelerating over the last several decades. A thorough understanding of past developments is crucial to anticipating the future intelligently. The trends that have driven evolution historically often persist, and continue to be influential in the future. With this in mind, this article briefly outlines the historical and current trends in bariatric surgery, and follows the trajectory of these trends into the future to anticipate the technologies and techniques that will be most important to the field in the coming years.

An update on less invasive and endoscopic techniques mimicking the effect of bariatric surgery

Obesity (BMI 30-35 kg/m(2)) and its associated disorders such as type 2 diabetes, nonalcoholic fatty liver disease, and cardiovascular disease have reached pandemic proportions worldwide. For the morbidly obese population (BMI 35-50 kg/m(2)), bariatric surgery has proven to be the most effective treatment to achieve significant and sustained weight loss, with concomitant positive effects on the metabolic syndrome. However, only a minor percentage of eligible candidates are treated by means of bariatric surgery. In addition, the expanding obesity epidemic consists mostly of relatively less obese patients who are not (yet) eligible for bariatric surgery. Hence, less invasive techniques and devices are rapidly being developed. These novel entities mimic several aspects of bariatric surgery either by gastric restriction (gastric balloons, gastric plication), by influencing gastric function (gastric botulinum injections, gastric pacing, and vagal nerve stimulation), or by partial exclusion of the small intestine (duodenal-jejunal sleeve). In the last decade, several novel less invasive techniques have been introduced and some have been abandoned again. The aim of this paper is to discuss the safety, efficacy, complications, reversibility, and long-term results of these latest developments in the treatment of obesity.

Endoscopic treatment of obesity

Obesity is a worldwide epidemic, complex metabolic disease associated with a variety of severe comorbidities. Bariatric surgery provides the patients with the benefits of sustained weight loss and improves obesity-related comorbidities, but can result in potentially life-threatening complications. Gastrointestinal endoscopy has recently been proposed as a scarless and noninvasive approach to obesity. Most of the current endoluminal devices and techniques are comparable to restrictive surgery. A variety of medical devices and procedures have been evaluated in recent years; however, with the exception of the intragastric balloon, evaluation of all the other endoluminal procedures is limited by the numbers of patients treated, the short follow-up and especially by the study design. Today, only a few devices have been evaluated in randomized controlled trials. The preliminary results of the first studies are extremely promising, but definitive statements cannot be drawn yet.

Obesity and bariatrics for the endoscopist: new techniques

Obesity and its associated conditions, including type 2 diabetes and cardiovascular disease, have reached epidemic proportions. Gastrointestinal weight loss surgery (GIWLS) shows the most promise in achieving significant and sustained weight loss and diabetes resolution. However, a large mismatch exists between the magnitude of the obesity epidemic and the number of surgical procedures performed to produce a significant shift in the distribution of obesity on a population level. This mismatch is fueled by high surgical costs, morbidity and mortality associated with surgical interventions, and the fact that the greatest public health burden of obesity comes from those around the center of the population body mass index distribution with mild to moderate obesity, rather than those at the distribution tail with severe obesity that GIWLS targets. New endoscopic methods, capitalizing on advances in our understanding of the physiological mechanisms by which GIWLS works, are developing to provide viable alternatives in the treatment of bariatric surgical complications, and for the primary treatment of obesity. These methods may have the added advantage of reduced invasiveness, reversibility, cost-effectiveness, and applicability to a larger segment of the population with moderate obesity.

A pathway to endoscopic bariatric therapies

The American Society for Gastrointestinal Endoscopy (ASGE) is dedicated to advancing patient care and digestive health by promoting excellence in gastrointestinal endoscopy. The American Society for Metabolic and Bariatric Surgery (ASMBS) is dedicated to improving public health and well-being by lessening the burden of the disease of obesity and related diseases. They are the largest professional societies for their respective specialties of gastrointestinal endoscopy and bariatric surgery in the world. The ASGE/ASMBS task force was developed to collaboratively address opportunities for endoscopic approaches to obesity, reflecting the strengths of our disciplines, to improve patient and societal outcomes. This white paper is intended to provide a framework for, and a pathway towards, the development, investigation, and adoption of safe and effective endoscopic bariatric therapies (EBT).

Endoscopic solutions for weight loss

PURPOSE OF REVIEW

Gastroenterologists will likely play a critical role in the treatment of obesity and its comorbidities, as novel endoluminal approaches demonstrate their safety and efficacy over the coming years. Understanding the relative advantages and shortcomings of the endoscopic tools and procedures currently under investigation will provide the gastroenterologist with valuable insight into the future of endoscopic procedures for weight loss.

RECENT FINDINGS

Endoscopic restrictive procedures, intestinal sleeves, and intragastric balloons have demonstrated short-term efficacy in inducing weight reduction and in reversing the comorbidities of obesity with an acceptable risk profile. Several endoscopic tools have also demonstrated effectiveness as revisional tools for reversing weight gain after bariatric surgery.

SUMMARY

A plethora of endoscopic tools and procedures are under investigation for primary and revisional obesity management, and these may offer new weight loss options to a variety of different patient populations.

Current status of endoluminal bariatric procedures for primary and revision indications

Endoscopic bariatric procedures are gaining traction as possible minimally invasive treatment modalities for obesity. This article focuses on the various endoscopic devices and procedures that pertain to primary and revisional treatments. Additionally, the article discusses the potential for applying these various devices and procedures to other points of intervention, including early intervention, bridge to surgery, and primary metabolic treatment (eg, diabetes management). Devices that are currently in human use are preferentially discussed, followed by references to devices that may see clinical use in the near future.