30 Obesity: Endoscopic Approaches
Andrew Storm, Steven Edmundowicz, and Christopher Thompson
Obesity is a lifelong condition that requires long-term multidisciplinary management focusing on lifestyle changes and dietary intervention and may include pharmacologic agents, endoscopic therapies, or surgery to achieve the desired outcome of weight loss and comorbidity reduction. The management of obesity is evolving and will likely be best delivered in multidisciplinary centers with expertise in all aspects of therapy. The endoscopic management of obesity is a relatively new and expanding concept in therapeutic endoscopy. Limited availability of bariatric surgeons, risk aversion for invasive surgical techniques, and rapidly increasing technology around minimally invasive endoscopic techniques are driving the field of “bariatric endoscopy.” Endoscopic approaches to weight loss include gastric restriction techniques, space-occupying devices, and metabolic bypass (barrier or aspiration) devices. While long-term data for these techniques are still being pursued, endoscopists must be aware of these techniques and devices as they are likely to encounter them in clinical practice, and should be prepared to counsel patients who may inquire about them.
30.2 Obesity: Endoscopic Approaches
Just over one-third of the population of the United States is obese, and the prevalence of obesity is increasing in many countries. In the United States the cost of managing obesity and its direct complications are estimated to total US$147 billion to 210 billion, or 21% of all U.S. health expenditure, emphasizing the health and economic impact of this highly prevalent disease state. 1 While surgical approaches to morbid obesity have historically been the mainstay of procedure-induced weight loss in this population, it has become apparent that the number of patients who qualify for bariatric surgery vastly overwhelms the availability of surgeons capable of performing these procedures. 2 , 3 Furthermore, the morbidity of surgery may be considered unacceptably high in some obese patients, leaving something to be desired.
Over the past two decades, endoscopic weight loss techniques have been developed and are gaining popularity. Generally speaking, endoscopic procedures for bariatric patients have aimed to affect the burden of both sheer excess body weight as well as comorbid medical conditions. Population studies are clear that many medical conditions caused by or related to obesity and the metabolic syndrome are improved with modest weight loss including, but not limited to, hypertension, hyperlipidemia, obesity hypoventilation, obstructive sleep apnea, insulin resistance, hyperglycemia, and arthritis. Techniques for both endoscopic revision of previous bariatric surgery and primary antiobesity devices, platforms, and procedures are available. While the field of bariatric endoscopy is still in development, it benefits any endoscopist to understand and appreciate these technologies, as he or she will be increasingly encountered in the clinical arena. Within this chapter, we will discuss the primary and revision weight loss procedures being performed endoscopically, but do not address the complications of bariatric surgery, nor their endoscopic management, which may also be of interest to the practicing endoscopist. Finally we will report experimental techniques that are on the horizon.
30.3 Diagnostic Approach and the Multidisciplinary Obesity Center Concept
Given the relatively noninvasive techniques available to the endoscopist, most patients seeking weight loss therapy may be considered for one of several endoscopic weight loss techniques. A patient’s body mass index (BMI), comorbid conditions, history of surgery, and personal weight loss goals will determine the specific technique to be used case-by-case. This is best delivered in a multidisciplinary center (either real or virtual) involving experts in obesity assessment, lifestyle management, nutritional management, pharmacologic agents, endoscopic therapies, and surgery. It should also include access to psychological support and cosmetic surgery for complete patient management. Patients must understand that obesity management is a lifelong process that requires active intervention on their part and the use of specific medications, devices, or techniques to maintain their health. Different endoscopic techniques and devices may assist in weight loss and mitigation of obesity-related complications across a wide range of BMI. Comorbid conditions, which may limit surgical techniques, should be considered when choosing candidates for bariatric endoscopic procedures. However, the minimally invasive nature of transoral flexible endoscopic therapy makes it often feasible in even the most medically complex patients.
30.3.1 General Approach, Equipment, and Techniques
Practice Setting: A Bariatric Center
An office specializing in the care of bariatric patients must incorporate larger and sturdier waiting room seating, examination tables, and stretchers, outfitted to safely and comfortably accommodate bariatric patients. A multidisciplinary approach to the bariatric patient utilizing nutritionists, behavior counselors, and multispecialty medical team is necessary to ensure 360-degree management of factors that may contribute to and complicate effective management of the patient’s obesity. Having these adjunctive supports in place is critically important to the long-term success of any onetime (or repeated) surgical or endoscopic treatment.
Preprocedural Clinic Evaluation
A standardized preoperative evaluation is considered prior to bariatric surgery, and should be similarly employed prior to endoscopic bariatric procedures. Patients are evaluated for conditions that may preclude, modify, or delay their procedure.
A standard prebariatric procedure evaluation according to guideline recommendations includes the following:
Ruling out Helicobacter pylori (via endoscopic or noninvasive testing) to avoid future bleeding events, including bleeding ulceration of the excluded stomach will be more difficult to evaluate and treat postoperatively
Esophagogastroduodenoscopy (EGD) to evaluate for presence of esophagitis, Barrett’s esophagus and varices, hiatal hernia, gastric polyps and ulcers, and tumors
When evaluating the obese patient in clinic prior to any planned surgical or endoscopic bariatric procedure, several important considerations come to the forefront. At a minimum, a onetime clinic visit to evaluate a candidate’s medical history, physical examination, and commitment to lifestyle changes should occur. One should take note of comorbid conditions that may make procedural sedation more difficult for the patient. Some endoscopic techniques may be able to be safely performed with only conscious sedation. Patients should be made aware of both medical weight management techniques including pharmacotherapeutics (not discussed in this endoscopy-themed text) and surgical techniques. Dietary and lifestyle modifications are and must remain the cornerstone of obesity management. Alone, intensive lifestyle modifications have been reported to result in up to 5 to 10% total body weight loss at 1 year. 4 Bariatric surgery, including Roux-en-Y gastric bypass (RYGB), gastric banding, and sleeve gastrectomy, is superior to lifestyle interventions with 1-year percent excess weight loss of 62 to 74%, 33 to 34%, and 51 to 70%, respectively 5 (▶Fig. 30.1, ▶Fig. 30.2). While mortality rates associated with bariatric surgery are less than 0.5%, adverse event rates range from 10 to 17% and reoperation rates range from 6 to 7%. This information may help the patients in making an informed decision regarding their preferred avenue of treatment.
It is an accepted practice, if not recently completed, to check a complete blood count (CBC) and thyroid-stimulating hormone (TSH) in most patients, especially if symptoms of anemia or hypothyroidism are present. The CBC is used to screen for evidence of iron deficiency anemia, and TSH to screen for hypothyroidism, either of which may result in excess weight gain that may respond to medical supplementation.
A thorough review of the patient’s diet and exercise regimen is undertaken, and the patient is counseled on appropriate dietary and exercise changes prior to any procedural intervention. We advise a strict 1,200-calorie diet (▶Table 30.1) and the United States’ Centers for Disease Control and Prevention (CDC) weekly minimum exercise regimen of 2.5 hours moderate-intensity aerobic activity in addition to muscle-strengthening resistance training twice weekly. Guidelines from the American Society for Metabolic and Bariatric Surgery (ASMBS) for a patient’s perioperative nutritional and medical support and evaluation exist, though these may not apply to a patient undergoing a lower-risk minimally invasive endoscopic procedure. 6
Once a patient has been medically evaluated and has decided to pursue an endoscopic bariatric procedure, it is an accepted practice to have the patient undergo screening EGD to assess his or her anatomy and determine the procedure approach that would most benefit the patient’s specific case. This screening EGD is also important if the patient previously underwent a bariatric surgical procedure in order to evaluate for postoperative complications including gastrogastric fistula, foreign body (like suture and staples), or dilated pouch or stoma, and also serves to exclude any disorder which may limit, preclude, or delay an endoscopic bariatric procedure, for example a cancer or ulcer. Once this clinical evaluation and EGD are completed, therapeutic planning of the endoscopic approach may ensue (▶Fig. 30.3).
Given that obesity is a chronic disease, and management of obesity requires a lifelong commitment, we do also require that our patients follow up in clinic after their procedure to evaluate for any complications of therapy including malnutrition and to encourage ongoing weight loss strategies and appropriate referral to subspecialty assistance as needed (i.e., endocrinology, nutritionist, physiotherapist).
30.3.2 Therapeutic Approaches: Currently Available Techniques
Patients with Native (Nonsurgical) Anatomy
The endoscopic approach to weight loss in the obese patient depends first on their surgical history. In the patient with native gastric anatomy, several devices and primary bariatric endoscopic techniques have been developed and studied with varying rates of success. Endoscopic techniques include space-occupying devices such as an intragastric balloon, gastric aspiration devices, barrier devices including the duodenal sleeve, and gastric partitioning procedures whereby restriction of the gastric lumen is created through endoscopic suturing or tissue plication. These devices and techniques are described below.
30.3.3 Gastric Techniques
The concept of an intragastric balloon for restriction and satiety is not a new concept, and in fact one was available on the U.S. market for a short time in the 1980s, only to be withdrawn due to relatively common occurrence of serious adverse events. In the interim, device improvements aimed at reducing complications have led to two intragastric balloon devices that have been Food and Drug administration (FDA)-approved as of 2015 and are available on the market (Orbera; Apollo Endosurgery, Austin, Texas and ReShape Duo; Reshape Medical, San Clemente, California). These devices are approved for use in patients with BMI range of 30 to 40 kg/m2, though the ReShape device carries the additional requirement of one or more obesity-related comorbid condition(s). These are contraindicated in patients with prior gastric surgery, bariatric surgery, inflammatory condition, mass or bleeding condition, to name a few. The intragastric balloon concept consists of a saline-filled silicone implant that is placed under endoscopic guidance into the stomach and left in place for up to 6 months, at which time the device must be removed, though it may be immediately replaced with a new balloon. Removal is accomplished with specialized retrieval tools. Intragastric balloons are considered a cosmetic implant in the United States at the time of this publication and thus require a relatively large out-of-pocket expense. This inconvenience is anticipated to change in the future, as other bariatric devices including the laparoscopic gastric band also required out-of-pocket payment at one time before gaining coverage by most insurance carriers.
The Orbera device (also known as the Bactiguard Infection Protection [BIP] balloon) is well studied and has been placed in more than 220,000 patients internationally as of 2014 (▶Fig. 30.4). A meta-analysis of 3,698 patients revealed average weight loss at 6 months of 14.7 kg or 32.1% excess weight loss and BMI reduction of 5.7 kg/m2. 7 In studies to date, at least 50% of this weight loss is maintained at 12 months, but longer-term efficacy data are lacking. Orbera has also been studied as a bridge to bariatric surgery in superobese patients (average BMI 66.5 kg/m2) resulting in average BMI loss of 5.5 kg/m2, significant decrease in systolic blood pressure, decreased surgical complications, and shorter surgical procedure times. 8 Weight loss at 1 year after bariatric surgery was similar between the patients who received Orbera prior to the procedure versus those who did not. Studies have also revealed significant improvements or resolution of both diabetes and depression in patients who underwent Orbera therapy. 9 , 10 The ReShape balloon includes two saline-filled silicone spheres (▶Fig. 30.5a). It was FDA approved based on data from the REDUCE Pivotal trial, a prospective, sham-controlled, double-blinded randomized multicenter study in 330 obese patients. Mean BMI was 35.4, and patients who received the device experienced on average 25.1% excess weight loss at 24 weeks. Adverse events include nausea and cramping in most patients, with more serious complications including device deflation reported in 6% and gastric ulcers in 10% of patients. 11 The newest FDA-approved addition to the IGB market is the Obalon balloon system. (▶Fig. 30.5b). This device involves the sequential placement of up to 3 swallowed, gas-filled intragastric balloons, which are also approved for 6 months of therapy. Endoscopy is not required for placement of the device(s). A multicenter randomized sham controlled study of 387 patients demonstrated 24.9% total weight loss at 6 months and 24.8 percent excess weight loss at 9 months. Other competing intragastric balloon devices are likely to join the market in coming years, including models that may be swallowed like a pill and then filled with a small catheter negating the need for endoscopy or sedation.