Human experience with an endoluminal, endoscopic, gastrojejunal bypass sleeve

Updates in metabolic bariatric endoscopy

Obesity and its associated comorbid conditions have been increasing globally. Endoscopic bariatric and metabolic therapies (EBMTs) were initially designed to replicate bariatric surgery physiology for those who are not or choose not to be surgical candidates. Now, newer procedures target the complicated pathophysiology underlying obesity and its comorbidities. EBMT has been categorized based on its therapeutic target (stomach or small intestine), but innovations have expanded to include extraintestinal organs including the pancreas. Gastric EBMTs, namely space-occupying balloons, gastroplasty with suturing or plication, and aspiration therapy, are primarily used for weight loss. Small bowel EBMTs are designed to cause malabsorption, epithelial endocrine remodeling, and other changes to intestinal physiology to ultimately improve the metabolic comorbidities of obesity rather than induce weight loss alone. These include duodenal mucosal resurfacing, endoluminal bypass sleeves, and incisionless anastomosis systems. Extraluminal or pancreatic EBMT is aimed to restore the production of normal pancreatic proteins that are involved in the progression of type 2 diabetes. This review discusses the current and new technologies of metabolic bariatric endoscopy, their pros and cons, and areas for future research.

Overview on the endoscopic treatment for obesity: A review

Obesity rates have increased, and so has the need for more specific treatments. This trend has raised interest in non-surgical weight loss techniques that are novel, safe, and straightforward. Thus, the present review describes the endoscopic bariatric treatment for obesity, its most recent supporting data, the questions it raises, and its future directions. Various endoscopic bariatric therapies for weight reduction, such as intragastric balloons (IGBs), aspiration therapy (AT), small bowel endoscopy, endoscopic sleeve gastroplasty, endoluminal procedures, malabsorption endoscopic procedures, and methods of regulating gastric emptying, were explored through literature sourced from different databases. IGBs, AT, and small bowel endoscopy have short-term effects with a possibility of weight regain. Minor adverse events have occurred; however, all procedures reduce weight. Vomiting and nausea are common side effects, although serious complications have also been observed.

Small intestine-targeted endoscopic bariatrics: Current status and future perspectives

The global obesity epidemic shows no signs of slowing down. Endoscopic bariatric and metabolic therapies (EBMTs) are being increasingly adopted as treatment options for obesity and obesity-related comorbidities, due to their minimally invasive nature and ease of delivery. According to the site of action along the gastrointestinal tract, EBMTs can be divided into two categories: gastric EBMTs, and small intestine-targeted EBMTs. Unlike gastric EBMTs, which work through a volume-restricting mechanism leading to early satiety and reduced caloric intake, small intestine-targeted EBMTs can be metabolically beneficial through foregut and/or hindgut pathways independent of weight loss, and therefore have great potential for the treatment of obesity-related metabolic comorbidities such as type 2 diabetes. Although none of the small intestine-targeted EBMTs have been approved by the US Food and Drug Administration to date, their clinical efficacy and safety have been extensively explored in investigational trials. This review aims to summarize and provide a comprehensive understanding of small intestine-targeted EBMTs in clinical and preclinical settings, and to further discuss their potential mechanisms of action.

Advances in endobariatrics: past, present, and future

The obesity epidemic in the USA and worldwide is well documented and continues to grow. Endoscopic metabolic and bariatric therapies may offer a less invasive approach than surgical intervention. This article will review advances in endobariatrics over the last several decades, addressing the past and current state of bariatric and metabolic endoscopy. Food and Drug Administration-cleared devices and interventions currently under investigation are described including gastric devices, gastric remodeling procedures, small-bowel devices, duodenal ablation, as well as procedures to address weight regain after bariatric surgery. Future studies evaluating gastric and duodenal combination therapy, adjunctive pharmacotherapy, as well as individualized precision-health algorithms are underway.

Bariatric endoscopy: from managing complications to primary metabolic procedures

Obesity is a worldwide epidemic and is the second leading cause of preventable death. The approach to treating obesity involves a multidisciplinary approach including lifestyle interventions, pharmacological therapies, and bariatric surgery. Endoscopic interventions are emerging as important tools in the treatment of obesity with primary and revisional bariatric endoscopic therapies. These include intragastric balloons, aspiration therapy, suturing and plication, duodenal-jejunal bypass liners, endoscopic duodenal mucosal resurfacing, and incisionless magnetic anastomosis systems. Endoscopic interventions have also demonstrated efficacy in treating complications of bariatric surgery. Approaches include stenting, endoscopic internal drainage, and endoscopic vacuum-assisted closure. This review aimed to discuss the current endoscopic procedures used as primary and revisional bariatric therapy including those used for managing bariatric surgical complications.

Bariatric and Metabolic Endoscopy: A New Paradigm

The prevalence of obesity, type 2 diabetes mellitus, and metabolic syndromes is increasing globally. Minimally invasive metabobariatric (MB) endoscopic therapies are adjunct treatments that can potentially bridge the gap between surgical interventions and medical therapy. A growing number of MB techniques are becoming available, allowing for more personalized and patient-targeted treatment options for specific disease states. MB techniques are less invasive than surgery and can precisely target different parts of the gastrointestinal tract that may be responsible for the pathophysiology of obesity and metabolic syndromes such as type 2 diabetes mellitus. These alternatives should be selected on an individualized patient basis to balance the expected clinical outcomes and desired anatomical targets with the level of invasiveness and degree of acceptable risk. Each MB intervention presents great flexibility allowing for a tailored intervention and different levels of patient engagement. Patient awareness and motivation are essential to avoid therapy withdrawal and failure. Differences between MB procedures in terms of weight loss and metabolic benefit will be discussed in this review, along with the insights on clinical decision-making processes to evaluate the potential of further evolution and growth of bariatric and metabolic endoscopy.

The current state of bariatric endoscopy

A variety of endoscopic bariatric and metabolic treatments (EBMTs) have been developed in recent years to combat the growing prevalence of obesity in the United States (US) and worldwide. This manuscript reviews the current state of bariatric endoscopy, detailing all US Food and Drug Administration (FDA) approved EBMTs including space-occupying intragastric balloons (IGBs), aspiration therapy, and endoscopic tissue apposition devices. Additionally, this review describes non-FDA approved treatments including additional IGBs, endoluminal bypass liners, duodenal mucosal resurfacing, and endoscopically placed anastomosis devices.

Various Novel and Emerging Technologies in Endoscopic Bariatric and Metabolic Treatments

Obesity, along with its comorbidities, has become a significant public health concern worldwide. Bariatric surgery is considered the most effective treatment modality; however, only 2% of patients with obesity undergo bariatric surgery. Endoscopic bariatric and metabolic therapies (EBMTs) are emerging alternatives to traditional bariatric surgery for patients who are not eligible for or do not prefer surgical treatment. EBMTs are generally categorized as space-occupying, gastric restrictive, aspiration, and small bowel therapies. We aimed to review various non-balloon and non-gastroplasty devices with available clinical data and discuss the possible mechanisms of action, efficacy, and safety profile of these EMBTs.

New technologies and advances in weight loss therapy

Bariatric surgery is the most effective treatment for obesity and its comorbidities but there are barriers that prevent its general acceptance. The growing obesity epidemic has resulted in the need for the creation of new, less invasive treatments, with a wide margin of safety and effectiveness for conditioning weight loss, at least greater than that resulting from treatment based on diet and exercise. Emerging therapies include devices that are endoscopically placed and removed, classified as: space-occupying devices, restrictive or anatomic-remodeling procedures, endoluminal bypass, and duodenal mucosal resurfacing. Percutaneous techniques and less invasive surgeries are also included. In general, results have shown improvement in glucose metabolism in diabetic patients. With respect to weight loss, results do not surpass those of bariatric surgery, but are better than results with conservative treatment (diet and exercise) and have a low rate of adverse events. Clinical use of a new technique should be carried out within a multidisciplinary management program that includes nutritional, psychologic, physical activity, and medical support. It must be understood that novel therapies are not being created to substitute bariatric surgery, but rather to increase treatment options in the general population, with greater reach and impact. The aim of the present study was to provide an up-to-date literature review on emerging technologies for the treatment of obesity.

New Devices for Endoscopic Treatments in Gastroenterology: A Narrative Review

Endoscopy is in a period of continuous innovations in terms of image quality, endoscopes, post-processing software and lastly, application of Artificial Intelligence. Therapeutic boundaries have expanded, widening the grey zone between endoscopy and surgery, and increasing endoscopic approaches in clinical scenarios where, until a few years ago, surgery was the only option. New scopes and accessories have made it easier to access critical areas such as the biliary tree and the small bowel intestine. In the field of hepato-pancreato-biliary endoscopy (HPB), it is now possible to directly access the biliary ducts or cystic lesions though dedicated stents and scopes, rather than having to rely only on fluoroscopy and ultrasound, increasing the diagnostic and therapeutic options by applying a three-dimensional approach. This narrative review will give an overview of some of the most relevant emerging fields in luminal and HPB endoscopy, highlighting advantages and main limitations of the techniques, and providing considerations for future development.

Metabolic endoscopy: Today's science-tomorrow's treatment

Obesity, type 2 diabetes mellitus (T2DM) and nonalcoholic steatohepatitis are increasing pandemic metabolic disorders. Lifestyle intervention (LSI) is the cornerstone treatment for these but is successful as standard care alone in only a few patients, given the modest weight loss at mid and long term. Conversely, bariatric surgery is the only proven effective treatment for these metabolic disorders, albeit offered only in a small percentage of cases because of its invasiveness and cost. The so-called endoscopic bariatric and metabolic therapies (EBMTs) include new, less-invasive technologies such as intragastric balloons, aspiration therapy, endoscopic sleeve gastroplasty, diversion devices, and duodenal mucosal resurfacing, currently at various stages of development. EBMTs, as an add-on to LSI, might represent an effective treatment filling the gap between medical and surgical management, taking into account, however, that obesity and its associated comorbidities constitute a chronic disease that needs lifelong therapy. In this review we describe the current scientific evidence surrounding EBMTs as well as future opportunities for such treatments in managing obesity and metabolic disorders.

Bariatric and Metabolic Therapies Targeting the Small Intestine

The global prevalence of obesity and type 2 diabetes (T2DM) necessitates an increased reliance on effective and safe endoscopic therapies. While surgery is highly effective, endoscopic therapies may be able to reach a greater number of affected individuals and help to reduce the burden of disease worldwide. Although current endoscopic treatments entail space occupying gastric devices as well as suturing or plication, innovative, non-Food and Drug Administration (FDA) approved small bowel specific endoscopic bariatric and metabolic therapies have been developed within the last several years. Small intestine therapies include endoluminal bypass liners, duodenal mucosal resurfacing, endoscopic anastomosis systems, and restricted duodenal flow treatments. These endoscopic bariatric and metabolic therapies rely upon foregut and hindgut mechanisms to achieve weight loss and improve glucose homeostasis. This review will detail these important small bowel mechanisms and evaluates current small bowel endoscopic treatments.

Procedures and devices for bariatric and metabolic endoscopy

Obesity is a leading cause of preventable death in developed countries, with a rising incidence over time. Lifestyle modification, pharmacotherapy, and bariatric surgery are the mainstays of bariatric therapy, even though burdened by several limitations in terms of efficacy or safety. Bariatric endoscopy has been developed in the last decades as a minimally invasive alternative, aimed to bridge the gap between conservative and interventional conventional therapies. This review aims to provide an updated overview of the bariatric and metabolic available endoscopic procedures and to drive the choice of the right procedure for the right patient.

Metabolic endoscopy by duodenal mucosal resurfacing: expert review with critical appraisal of the current technique and results

INTRODUCTION

Duodenal mucosal resurfacing (DMR) is an endoscopic procedure for type 2 diabetes (T2D) consisting of circumferential hydrothermal ablation of the duodenal mucosa.

AREAS COVERED

A review was conducted on the reports available up to March-2020. On a total of 79 patients, DMR induced a significant mean HbA1c, FPG and HOMA-IR reduction at 6 months (0.9 ± 0.2%, 1.7 ± 0.5 mmol/L and 2.9 ± 1.1 mUI/L respectively - P < 0.001). DMR metabolic efficacy directly correlates with the length of the ablated mucosa (mean 3 months HbA1c reduction 1.2% vs 2.5% after short and long ablation respectively - P < 0.05), while it is independent of weight-loss. Severe AEs were registered in 3.7% of the cases.

EXPERT OPINION

DMR plays a promising role in metabolic impairment improvement inducing a morpho-functional duodenal alteration not necessarily depending on weight-loss. Technical-functional improvements of the device and appropriate training aimed at its correct use are needed to lower the rate of severe AEs and technical failure. The current role of DMR needs to be clarified, but it might be proposed for poorly controlled T2D in accurately selected patients. Evidence on DMR is still scanty and further research is mandatory to standardize the endoscopic technique and its indications.

Current and Future Endoscopic Weight Loss Solutions

Obesity poses a significant health care concern in the United States, with 39.8% of adults being classified as obese. Several different methods have been introduced to combat obesity, from medical therapy to surgical options. Bariatric surgery has been demonstrated to be superior to medical therapy alone for weight loss in obese patients. Despite this information, only about 1% of eligible patients undergo bariatric surgery per year. The reason for this treatment gap is multifactorial, but patient apprehension to undergo surgery is a major driving force. Many patients perceive bariatric surgery as dangerous, and believe that living with their current weight is safer than undergoing surgery. To combat this treatment gap, endoscopic therapies have been developed to reach more patients in a less invasive way. This article will review endoscopic treatment options currently available and approved by the Food and Drug Administration, as well as other treatment modalities that are currently in development.

Biodegradable polymer-nanoclay composites as intestinal sleeve implants installed in digestive tract for obesity and type 2 diabetes treatment

Obesity and type 2 diabetes have become serious health problems in 21st century. Development of non-invasive treatment to treat obesity and type-2 diabetes is still unmet needs. For targeting on this, one of the promising treatments is to implant an intestine sleeve in the gastrointestinal tract for limitation of food absorption. In this context, biodegradable polymer intestine sleeve was composed of polycaprolactone (PCL), poly-DL-lactic acid (PDLLA) and disk-shape nano-clay (Laponite®), and fabricated as an implantable device. Here, Laponite® as a rheological additive to improve the compatibility of PCL and PDLLA, and the polymers/clay composites were also evaluated by scanning electron microscopy SEM analysis and mechanical measurements. The mass ratio 90/10/1 of PCL/PDLLA/Laponite® composite was selected for fabrication of intestine sleeve, because of the highest toughness and flexibility, which are tensile strength of 91.9 N/mm² and tensile strain of 448% at the failure point. The prepared intestine sleeve was implanted and deployed at the duodenum in type2 diabetic rats, providing significant benefits in control of the body weight and blood glucose, while compared with the non-implanted type 2 diabetic rats. More importantly, the food intake records and histopathological section reports presented that the implanted rats still have normal appetites and no noticeable acute symptoms of inflammation in the end of the test. These appreciable performances suggested the implantation of biocompatible polymer composites has a highly potential treatment for obesity and type 2 diabetes.

Endoscopic bariatric and metabolic therapies: Another tool for the management of diabetes and obesity

Endoscopic bariatric and metabolic therapies (EBMTs) have sparked significant interest as minimally invasive therapeutic options for weight loss. Although bariatric surgery remains an effective option for sustained weight loss and improvement in the metabolic syndrome, access and utilization are limited. Various EBMTs have been designed to emulate the physiologic effects of established surgical interventions, including space-occupying and non-space-occupying gastric therapies, gastric remodeling procedures, and small bowel therapies. This review discusses the safety and efficacy of available US Food and Drug Administration-approved minimally invasive endoscopic bariatric interventions, as well as those currently under investigation. In addition, the role of endoscopic revision after failed surgical intervention is discussed.

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.

Small Bowel Endoscopic Bariatric Therapies

Endoscopic bariatric therapies that emulate some of the principles of bariatric surgery have been developed as a less invasive option for the treatment of obesity and related comorbidities. Small bowel endoscopic bariatric therapies include bypass sleeves, incisionless anastomosis systems, and duodenal mucosal resurfacing. Clinical experience with small bowel devices suggests that endoscopic bariatric procedures can be safely implemented and that these devices are effective for both weight loss and metabolic improvement. Although the mechanisms behind these effects should be further elucidated, endoscopic bariatric therapies may be more effective and safer adjunctive interventions than lifestyle modifications and pharmacological regimens for patients with obesity or obesity-related comorbidities.

Endoscopic Interventions in the Treatment of Obesity and Diabetes

Obesity is a global health problem which is on the rise and is strongly associated with the development of type 2 diabetes and other comorbidities. Bariatric surgery is now an established treatment for both these conditions, leading to impressive results in weight loss and glycemic control. More recently, we have seen the development of various endoscopic devices as potential alternatives or adjuncts to bariatric surgery. In this state-of-the-art review, we outline the current landscape of endoscopic treatments available for the management of both obesity and diabetes, including the clinical evidence supporting their use, efficacy, safety, and potential mechanisms of action.

Devices and Endoscopic Bariatric Therapies for Obesity

PURPOSE OF REVIEW

In this review, we describe the FDA-approved and investigational devices and endoscopic bariatric therapies for the treatment of obesity. We focus on literature published in the past few years and present mechanisms of action as well as efficacy and safety data.

RECENT FINDINGS

Devices and endoscopic procedures are emerging options to fill the significant treatment gap in the management of obesity. Not only are these devices and procedures minimally invasive and reversible, but they are potentially more effective than antiobesity medications, often safer for poor surgical candidates and possibly less expensive than bariatric surgery. As many patients require a variety of management strategies (medications, devices, procedures, and/or surgery) in addition to lifestyle modifications to achieve clinically significant weight loss, the future of obesity treatment involves a multidisciplinary approach. Combinations of advanced treatment strategies can lead to additive or synergistic weight loss. This is an area that requires further investigation.

Totally endoscopic implant to effect a gastric bypass: 12-month safety and efficacy outcomes

BACKGROUND

Only a small percentage of candidates for bariatric surgery ever undergo a procedure for weight loss. Devices duplicating key effects of bariatric surgeries with removable, fully trans-oral implants could extend their benefits to patients unwilling to undergo anatomy-altering abdominal surgeries.

METHODS

Thirty-two obese subjects (mean BMI: 42.3) were enrolled in a prospective, multicenter, single-arm, feasibility trial of the first fully trans-oral endoscopic gastrointestinal bypass device. The device is a cuff attached to the distal esophagus by transmural anchors and connected to a 120-cm sleeve diverting undigested nutrients to the jejunum. Bodyweight, vital signs, adverse events, medications, HbA1c, fasting glucose, and lipids were collected at baseline and follow-up visits. Device status was endoscopically assessed every 6 months.

RESULTS

The fully trans-oral procedure was successful in all subjects without intraoperative adverse events or postoperative infections. Twenty-eight of 32 subjects (88%) remained implanted with continuing follow-up beyond their 12-month visit. At 12 months, the 32 subjects had lost an average of 44.8% of excess body weight, 17.6% of total body weight, 20.8 kg, and 7.5 BMI points. Weight loss depended on capture of ingesta by the esophageal cuff, with 18 of 32 subjects without visible gaps around their cuffs at the 6 month endoscopy having significantly greater EWL (53.6 vs. 33.4% in the remaining subjects, p < 0.002). Mean HbA1c and fasting glucose declined by 1.1% points and 29 mg/dL in type 2 diabetic subjects, 80% of whom had remission of their diabetes at 12 months.

CONCLUSION

This study demonstrates the feasibility, safety, and efficacy of a fully trans-oral gastrointestinal bypass implant. This purely endoscopic device may provide a valuable addition to the armamentarium of treatment available for the management of morbid obesity.

Endoluminal Treatments for Obesity and Related Hypertension: Updates, Review, and Clinical Perspective

PURPOSE OF REVIEW

Obesity is a global epidemic that continues to grow and results in related conditions such as hypertension and diabetes despite established interventions, thus suggesting the importance of new technologies.

RECENT FINDINGS

Endoscopic interventions are vast in scope and effectiveness. Intra-gastric balloons appear to dominate the field at this time, but a recent FDA-approved technique, the Aspire device, may soon cause a shift in the treatment paradigm. Short-term studies demonstrate optimistic results, yet long-term studies have not been performed. In addition, complications from these procedures are severe, resulting in significant morbidity when they occur. Treatment of bariatric surgery complications with endoscopic techniques is an expanding field that relies heavily on new innovation. The next few years in bariatric endoscopy promise to be turbulent and controversial. Endoscopic procedures for obesity will undoubtedly increase but are anticipated to do so at a slower rate than many projects. Bariatric surgery complications will continue to be treated by endoscopic means, and optimization of these procedures is on the horizon. This review will provide those who treat obesity-related hypertension on the current state of bariatric endoluminal procedures.

Endoscopic Medical Devices for Primary Obesity Treatment in Patients With Diabetes

IN BRIEF Several new endoscopic bariatric therapies have been approved by the U.S. Food and Drug Administration for the treatment of obesity, with many more devices and procedures undergoing investigational studies. This article describes these devices and procedures and special considerations for their use in patients with diabetes.

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.

Medical devices for the treatment of obesity

Obesity is a major public health concern that leads to numerous metabolic, mechanical and psychological complications. Although lifestyle interventions are the cornerstone of obesity management, subsequent physiological neurohormonal adaptations limit weight loss, strongly favour weight regain and counteract sustained weight loss. A range of effective therapies are therefore needed to manage this chronic relapsing disease. Bariatric surgery delivers substantial, durable weight loss but limited access to care, perceived high risks and costs restrict uptake. Medical devices are uniquely positioned to bridge the gap between more conservative lifestyle intervention and weight-loss pharmacotherapy and more disruptive bariatric surgery. In this Review, we examine the range of gastrointestinal medical devices that are available in clinical practice to treat obesity, as well as those that are in advanced stages of development. We focus on the mechanisms of action as well as the efficacy and safety profiles of these devices. Many of these devices are placed endoscopically, which provides gastroenterologists with exciting opportunities for treatment.

Endoscopic Bariatric and Metabolic Therapies: New and Emerging Technologies

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.

Small Bowel Target Devices and Techniques

The small bowel is a prime target for bariatric and metabolic endoscopic therapies. New insights into the mechanisms of action of surgical therapies have led to new endoscopic therapies for obesity, type 2 diabetes mellitus, and the metabolic syndrome. The development of endoluminal sleeves that bypass the proximal duodenum have replicated some of the effects of surgical bypass procedures. The endoscopic dual-path enteral bypass has created new and treatment options for these conditions. Duodenal mucosal resurfacing offers significant promise for diabetes management. It is hoped that a durable endoscopic therapy for these conditions will be defined and optimized.

Role of Malabsorptive Endoscopic Procedures in Obesity Treatment

The incidence of obesity is increasing, and more definitive treatment modalities are needed. Endoluminal procedures, including restrictive endoscopic procedures, endoscopic gastroplasty, and malabsorptive endoscopic procedures, can reduce weight in obese patients and control obesity-related comorbidities. Malabsorptive endoscopic interventions also offer the potential for an ambulatory procedure that may be safer and more cost-effective compared with laparoscopic surgery. Malabsorptive endoscopic intervention can induce weight reduction and improve obesity-related metabolic parameters, despite complications such as device migration, obstruction, and abdominal pain. Improvement in technique will follow the development of new devices.

Bariatric endoscopy: current state of the art, emerging technologies, and challenges

INTRODUCTION

Over the last few decades obesity has become a major health issue worldwide. Although dietary and lifestyle changes are the cornerstone of obesity management, it still poses a huge challenge for the majority of patients to permanently change their eating habits. Bariatric endoscopy represents an evolving filed of minimally invasive techniques and procedures for weight loss trying to respond to these challenges by developing new methods with the increasing role of endoscopists in the management of obesity. Areas covered: The aim of this article is to review the role and the advantages of bariatric endoscopy in the management of obesity by providing a comprehensive reference source and evaluating the currently available and emerging endoscopic devices and techniques for weight loss. Expert commentary: Endoscopic methods for weight loss represent a useful armamentarium in the management of obesity by providing improved effectiveness compared with medications, with a lower risk profile than traditional bariatric surgery. Although preliminary results of recently introduced methods are encouraging, many questions remain regarding the safety and efficacy of such interventions. Combining scientific background with advancements in technology is the key strategy for the further development of bariatric endoscopy.

Metabolic syndrome and the hepatorenal reflex

Insufficient hepatic O₂ in animal and human studies has been shown to elicit a hepatorenal reflex in response to increased hepatic adenosine, resulting in the stimulation of renal as well as muscle sympathetic nerve activity and activating the renin angiotensin system. Low hepatic ATP, hyperuricemia, and hepatic lipid accumulation reported in metabolic syndrome (MetS) patients may reflect insufficient hepatic O₂ delivery, potentially accounting for the sympathetic overdrive associated with MetS. This theoretical concept is supported by experimental results in animals fed a high fructose diet to induce MetS. Hepatic fructose metabolism rapidly consumes ATP resulting in increased adenosine production and hyperuricemia as well as elevated renin release and sympathetic activity. This review makes the case for the hepatorenal reflex causing sympathetic overdrive and metabolic syndrome in response to exaggerated splanchnic oxygen consumption from excessive eating. This is strongly reinforced by the fact that MetS is cured in a matter of days in a significant percentage of patients by diet, bariatric surgery, or endoluminal sleeve, all of which would decrease splanchnic oxygen demand by limiting nutrient contact with the mucosa and reducing the nutrient load due to loss of appetite or dietary restriction.

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.

Metabolic syndrome and the hepatorenal reflex

Insufficient hepatic O₂ in animal and human studies has been shown to elicit a hepatorenal reflex in response to increased hepatic adenosine, resulting in stimulation of renal as well as muscle sympathetic nerve activity and activating the renin angiotensin system. Low hepatic ATP, hyperuricemia, and hepatic lipid accumulation reported in metabolic syndrome (MetS) patients may reflect insufficient hepatic O₂ delivery, potentially accounting for the sympathetic overdrive associated with MetS. This theoretical concept is supported by experimental results in animals fed a high fructose diet to induce MetS. Hepatic fructose metabolism rapidly consumes ATP resulting in increased adenosine production and hyperuricemia as well as elevated renin release and sympathetic activity. This review makes the case for the hepatorenal reflex causing sympathetic overdrive and metabolic syndrome in response to exaggerated splanchnic oxygen consumption from excessive eating. This is strongly reinforced by the fact that MetS is cured in a matter of days in a significant percentage of patients by diet, bariatric surgery, or endoluminal sleeve, all of which would decrease splanchnic oxygen demand by limiting nutrient contact with the mucosa and reducing the nutrient load due to the loss of appetite or dietary restriction.

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.

Surgical cure for type 2 diabetes by foregut or hindgut operations: a myth or reality? A systematic review

BACKGROUND

Bariatric surgery results in remission of type 2 diabetes mellitus in a significant proportion of patients. Animal research has proposed the foregut and hindgut hypotheses as possible mechanisms of remission of T2DM independent of weight loss. These hypotheses have formed the basis of investigational procedures designed to treat T2DM in non-obese (in addition to obese) patients. The aim of this study was to review the procedures that utilise the foregut and hindgut hypotheses to treat T2DM in humans.

METHODS

A systematic review was conducted to identify the investigational procedures performed in humans that are based on the foregut and hindgut hypotheses and then to assess their outcomes.

RESULTS

Twenty-four studies reported novel procedures to treat T2DM in humans; only ten utilised glycated haemoglobin A1c (HbA1c) in their definition of remission. Reported remission rates were 20-40 % for duodenal-jejunal bypass (DJB), 73-93 % for duodenal-jejunal bypass with sleeve gastrectomy (DJB-SG), 62.5-100 % for duodenal-jejunal bypass sleeve (DJBS) and 47-95.7 % for ileal interposition with sleeve gastrectomy (II-SG). When using a predetermined level of HbA1c to define remission, the remission rates were lower (27, 63, 0 and 65 %) for DJB, DJB-SG, DJBS and II-SG.

CONCLUSIONS

The outcomes of the foregut- and hindgut-based procedures are not better than the outcomes of just one of their components, namely sleeve gastrectomy. The complexity of these procedures in addition to their comparable outcomes to a simpler operation questions their utility.

Bile Acids, FXR, and Metabolic Effects of Bariatric Surgery

Overweight and obesity represent major risk factors for diabetes and related metabolic diseases. Obesity is associated with a chronic and progressive inflammatory response leading to the development of insulin resistance and type 2 diabetes (T2D) mellitus, although the precise mechanism mediating this inflammatory process remains poorly understood. The most effective intervention for the treatment of obesity, bariatric surgery, leads to glucose normalization and remission of T2D. Recent work in both clinical studies and animal models supports bile acids (BAs) as key mediators of these effects. BAs are involved in lipid and glucose homeostasis primarily via the farnesoid X receptor (FXR) transcription factor. BAs are also involved in regulating genes involved in inflammation, obesity, and lipid metabolism. Here, we review the novel role of BAs in bariatric surgery and the intersection between BAs and immune, obesity, weight loss, and lipid metabolism genes.

Endoscopic Bypass Using Endobarrier Devices: Efficacy in Treating Obesity and Metabolic Syndrome

Obesity is a rapidly growing pandemic. Scope of pharmacotherapy and bariatric surgery in managing obesity is ever rising. The role of minimally invasive techniques to achieve preoperative weight loss and improve postbariatric surgery outcomes is an area of new interest. The initial experience with endobarrier devices in achieving weight loss among obese subjects has shown promising results. In addition, the impact of these interventions on comorbidities commonly associated with obesity like diabetes mellitus type 2 and hyperlipidemia has further expanded their potential for use in future. In this review article, we have summarized case report, prospective single and multicenter studies, and randomized-controlled trials describing the use of endobarrier devices. Indications, techniques, outcomes, limitations, and complications reported are discussed.

Bariatric surgery in class I obesity : a Position Statement from the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO)

Class I obesity conveys an increased risk of comorbidities, impairs physical and mental health-related quality of life, and it is associated to an increased psychosocial burden, particularly in women. The need for effective and safe therapies for class I obesity is great and not yet met by nonsurgical approaches. Eligibility to bariatric surgery has been largely based on body mass index (BMI) cut points and limited to patients with more severe obesity levels. However, obese patients belonging to the same BMI class may have very different levels of health, risk, and impact of obesity on quality of life. Individual patients in class I obesity may have a comorbidity burden similar to, or greater than, patients with more severe obesity. Therefore, the denial of bariatric surgery to a patient with class I obesity suffering from a significant obesity-related health burden and not achieving weight control with nonsurgical therapy simply on the basis of the BMI level does not appear to be clinically justified. A clinical decision should be based on a more comprehensive evaluation of the patient's current global health and on a more reliable prediction of future morbidity and mortality. After a careful review of available data about safety and efficacy of bariatric surgery in patients with class I obesity, this panel reached a consensus on ten clinical recommendations.

One-year human experience with a novel endoluminal, endoscopic gastric bypass sleeve for morbid obesity

INTRODUCTION

Here, we report the first series of patients with 1-year implantation of a novel, endoluminal, endoscopically delivered and retrieved gastro-duodeno-jejunal bypass sleeve (GJBS) (ValenTx, Inc. Carpinteria, CA, USA). In this report, we present the safety, feasibility of the device, weight loss, and changes in comorbidities.

METHODS AND PROCEDURES

A prospective, single-center, 12-month trial was designed. The patients are morbidly obese individuals who meet the NIH criteria for bariatric surgery. The GJBS is a 120-cm sleeve secured at the esophago-gastric junction with endoscopic and laparoscopic techniques that is designed to create an endoluminal gastro-duodeno-jejunal bypass. The device was implanted and, at the completion of the trial, retrieved with an endoscopic technique. The primary endpoints were safety and incidence of adverse events. The secondary outcomes included the percentage of excess weight loss (EWL) and changes in comorbidities, specifically glucose control, use of antihyperglycemics, and changes in hemoglobin A1C levels.

RESULTS

From July 2009 until October 2009, 13 patients were prospectively enrolled for the 1-year trial. The study included five men and eight women with a mean preoperative BMI of 42 kg/m(2). One patient was excluded, at the time of endoscopic evaluation, due to inflammation at the GE junction. Two additional patients required early explantation of the device, within the first 4 weeks, due to patient intolerance. Upon explant of the device, both patients' symptoms improved. In the remaining ten patients, the device was implanted, left in situ for 12 months, and then retrieved endoscopically. Safe delivery of the cuff at the gastro-esophageal junction was seen in all ten patients whom had device implants, without complication. No esophageal leak was seen immediately post-procedure or during follow-up. The sleeve device was well tolerated within the bowel lumen during the 12-month study, specifically, no bowel erosions, ulceration, or pancreatitis was observed. All ten patients reached the 1-year mark. Of the ten, six had fully attached and functional devices throughout the follow-up, verified by endoscopy. The mean percentage EWL, at 1 year, in this group was 54 %. In the remaining four patients, partial cuff detachment was observed at follow-up endoscopy. The percentage EWL was lower in this group. Of the six patients that reached a year with a fully attached device, five were followed at an average of 14-months post-explant (26 months from the time of device implant). These five maintained an average percentage EWL of 30 % at the 14-month post-explant follow-up. Co-morbidites measured included diabetes mellitus, hypertension, hyperlipidemia, and use of antihyperglycemics. Each of the measured comorbidities showed improvement during the 12-month trial.

DISCUSSION

The endoluminal, GJBS can be safely placed and retrieved. The short-term data show it is well tolerated with a good safety profile. It achieves excellent weight loss results with over 70 % of all comorbidities resolved or significantly improved.

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.

Intestinal sweet-sensing pathways and metabolic changes after Roux-en-Y gastric bypass surgery

Studies suggest that improvements in type 2 diabetes (T2D) post- Roux-en-Y gastric bypass (RYGB) surgery are attributable to decreased intestinal glucose absorption capacity mediated by exclusion of sweet taste-sensing pathways in isolated proximal bowel. We probed these pathways in rat models that had undergone RYGB with catheter placement in the biliopancreatic (BP) limb to permit post-RYGB exposure of isolated bowel to sweet taste stimulants. Lean Sprague Dawley (n = 13) and obese Zucker diabetic fatty rats (n = 15) underwent RYGB with BP catheter placement. On postoperative day 11 (POD 11), rats received catheter infusions of saccharin [sweet taste receptor (T1R2/3) agonist] or saline (control). Jejunum was analyzed for changes in glucose transporter/sensor mRNA expression and functional sodium-glucose transporter 1 (SGLT1)-mediated glucose uptake. Saccharin infusion did not alter glucose uptake in the Roux limb of RYGB rats. Intestinal expression of the glucose sensor T1R2 and transporters (SGLT1, glucose transporter 2) was similar in saccharin- vs. saline-infused rats of both strains. However, the abundance of SGLT3b mRNA, a putative glucose sensor, was higher in the common limb vs. BP/Roux limb in both strains of bypassed rats and was significantly decreased in the Roux limb after saccharin infusion. We concluded that failure of BP limb exposure to saccharin to increase Roux limb glucose uptake suggests that isolation of T1R2/3 is unlikely to be involved in metabolic benefits of RYGB, as restimulation failed to reverse changes in intestinal glucose absorption capacity. The altered expression pattern of SGLT3 after RYGB warrants further investigation of its potential involvement in resolution of T2D after RYGB.

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.

Duodeno-jejunal tube placement in an experimental model of obesity: effects on food behaviour and basal energy expenditure

BACKGROUND

Metabolic surgery can modulate weight as well as food intake and basal energy expenditure. In this study, we evaluate the effectiveness of duodenal exclusion by analysing anthropometric results, intake variations, food behaviour and calorimetric parameters.

METHODS

This is an experimental study with 8-week-old Sprague-Dawley male rats. The sequences used are as follows: Cafeteria diet for 3 weeks, followed by surgery and sacrifice at 4 weeks. Four experimental groups are as follows: two non-obese groups (n = 15; surgery = 10, sham = 5) and two obese groups by cafeteria diet (n = 15; surgery = 10, sham = 5). Surgery performed was duodenal exclusion with physical barrier. Weight, intake, glycaemia and basal energy expenditure by indirect calorimetry were monitored before and after surgery.

RESULTS

Weight changes in groups that underwent intervention were significant. The reduction in calorie consumption after surgery was significant in the obese intervention group despite an increased standard feed consumption (161 ± 11 vs 139 ± 13 Kcal/day, p < 0.05; due to a lower consumption of cafeteria diet). In non-obese animals, changes were transient. Basal energy expenditure decreased in both intervention groups: 6.2 ± 0.5 vs 5.5 ± 0.4 Kcal/kg/h in non-obese animals and 5.6 ± 0.3 vs 4.7 ± 0.3 Kcal/kg/h in obese animals (p < 0.05).

CONCLUSIONS

Duodeno-jejunal tube placement stops weight gain in obese and non-obese animals. In obese animals, there is an important qualitative change in appetite towards standard feed with a significant decrease in caloric intake. In non-obese animals, changes in quantitative intake are transient. This surgery decreases basal energy expenditure in obese animals. This may be attributed to an enhanced thermogenic effect of food and a slowing in the animal's weight gain.

The sum of many parts: potential mechanisms for improvement in glucose homeostasis after bariatric surgery

Bariatric surgery has emerged as the most durably effective treatment of type 2 diabetes (DM). However, the mechanisms governing improvement in glucose homeostasis have yet to be fully elucidated. In this review we discuss the various types of surgical interventions and the multitude of factors that potentially mediate the effects on glycemia, such as altered delivery of nutrients to the distal ileum, duodenal exclusion, gut hormone changes, bile acid reabsorption, and amino acid metabolism. Accumulating evidence that some of these changes seem to be independent of weight loss questions the rationale of using body mass index as the major indication for surgery in diabetic patients. Understanding the complex mechanisms and interactions underlying improved glycemic control could lead to novel therapeutic targets and would also allow for greater individualization of therapy and optimization of surgical outcomes.

Inpatient weight loss as a precursor to bariatric surgery for adolescents with extreme obesity: optimizing bariatric surgery

BACKGROUND

As the obesity epidemic takes its toll on patients stricken with the disease and our health care system, debate continues regarding the use of weight loss surgery and its long-term consequences, especially for adolescents. One subset of patients regarding whom there is increased controversy is adolescents with extreme obesity (BMI > 60 kg/m(2)) because the risk of complications in this weight category is higher than for others undergoing bariatric surgery. Several strategies have been suggested for this patient group, including staged operations, combined operations, intragastric balloon use, and endoluminal sleeve placement. However, the device options are often not available to adolescents, and there are no data regarding staged or combined procedures in this age group.

METHODS

All adolescents with BMI >60 kg/m(2) referred to our program were evaluated for inpatient medical weight loss prior to laparoscopic sleeve gastrectomy. The program utilizes a multidisciplinary approach with a protein-sparing modified fast diet, exercise, and behavioral modification.

RESULTS

Three patients completed the program, and each achieved significant preoperative weight loss through the inpatient program and successfully underwent bariatric surgery.

CONCLUSIONS

Presurgical weight loss via an inpatient program for adolescents with a BMI >60 kg/m(2) results in total weight loss comparable to a primary surgical procedure alone, with the benefit of decreasing the perioperative risk.

Gastrointestinal hormones and bariatric surgery-induced weight loss

Obesity continues to be a major public health problem in the United States and worldwide. While recent statistics have demonstrated that obesity rates have begun to plateau, more severe classes of obesity are accelerating at a faster pace with important implications in regards to treatment. Bariatric surgery has a profound and durable effect on weight loss, being to date one of the most successful interventions for obesity.

OBJECTIVE

To provide updates to the possible role of gut hormones in post bariatric surgery weight loss and weight loss maintenance.

DESIGN AND METHODS

The current review examines the changes in gastro-intestinal hormones with bariatric surgery and the potential mechanisms by which these changes could result in decreased weight and adiposity.

RESULTS

The mechanism by which bariatric surgery results in body weight changes is incompletely elucidated, but it clearly goes beyond caloric restriction and malabsorption.

CONCLUSION

Changes in gastro-intestinal hormones, including increases in GLP-1, PYY, and oxyntomodulin, decreases in GIP and ghrelin, or the combined action of all these hormones might play a role in induction and long-term maintenance of weight loss.

The evolution of minimally invasive bariatric surgery

BACKGROUND

Obesity is a pandemic associated with significant morbidity and mortality. This historical article charts the progress of successful strategies that have been used to tackle weight loss from dietary modifications to the development of surgical interventions that have subsequently evolved. It also provides a précis of the reported outcome data following minimally invasive bariatric procedures.

METHODS

A literature review was performed. All articles relevant to the progression of bariatric surgery and minimally invasive surgery were assessed, as were those articles that described the ultimate evolution, combination, and establishment of the two techniques.

RESULTS

This article charts the progression of early weight loss strategies, from early dietary modifications and pharmacologic interventions to initial techniques in small bowel bypass procedures, banding techniques, and sleeve gastrectomies. It also describes the simultaneous developments of endoscopic interventions and laparoscopic procedures.

CONCLUSIONS

A range of procedures are described, which differ in their success in terms of loss of excess weight and in their complication rates. Weight loss is greatest for biliopancreatic diversion followed by gastric bypass and sleeve gastrectomy and least for adjustable gastric banding. Bariatric surgery is an evolving field, which will continue to expand given current epidemiologic trends. Developments in instrumentation and surgical techniques, including single access and natural orifice approaches, may offer further benefit in terms of patient acceptability.