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Endoscopic Techniques for Weight Loss
Introduction
Obesity is the pandemic of the 21st century and is associated with considerable morbidity and mortality. Management of obesity depends on body mass index (BMI) and the presence of comorbidities, including heart disease, diabetes, hypertension, dyslipidemia, osteoarthritis, and sleep apnea. Approximately 1.6 billion adults are overweight; at least 400 million adults are obese. The World Health Organization projected that by 2015, approximately 2.3 billion adults would be overweight, and more than 700 million would be obese. Previously considered a problem only in high-income countries, the number of overweight and obese individuals is now dramatically increasing in low- and middle-income countries, particularly in urban settings.
At the present time, surgery is the only effective therapy for morbid obesity, defined as a BMI of 40 kg/m 2 or more, or as a BMI of 35 kg/m 2 or more in the presence of comorbidities. Bariatric surgery has been shown to be effective in the long-term and significantly reduces the risk of mortality associated with morbid obesity. In the United States, the indications for bariatric surgery increased by 80% during the period 1998–2004.
Bariatric surgery induces and maintains satisfactory weight loss while decreasing comorbidities in the overweight patient. Efficacy varies with the type of procedure, which can be divided into restrictive (lap band, sleeve gastrectomy), malabsorptive (biliopancreatic diversion), or a combination of both (gastric bypass). Although very effective, laparoscopic and surgical bariatric procedures have complication rates of 3% to 20% and mortality rates of 1%. Cardiopulmonary events and anastomotic leaks are the major sources of severe morbidities.
The demand for less invasive therapy for obesity led to the development of endoscopic technologies, potentially characterized by less invasiveness and fewer complications. Endoluminal surgery, performed entirely through a natural orifice, offers this potential for a less invasive weight loss procedure, possibly performed on an ambulatory basis, and might find its place in the current armamentarium for morbid obesity treatment, extending indications for treatment to patients with severe comorbidities and older age and even to non–morbidly obese patients. We review the various endoluminal techniques that are either in routine use or in clinical evaluation and address the role of endoscopy in management of weight regain occurring after bariatric surgery.
Endoscopic Options for Endoluminal Primary Treatment of Obesity
Similar to surgical procedures, the different options for endoluminal treatment of obesity can be divided between restrictive and malabsorptive procedures ( Table 43.1 ).
TABLE 43.1
Available Bariatric Endotherapy Technology
| Endoscopic Procedures | Mechanism | Human Applications | Limitations |
|---|---|---|---|
| Intragastric balloon | Restrictive | Prospective crossover study; > 2000 cases reported | Patient tolerance |
| Limited effect (6 mo) | |||
| Endoluminal vertical gastroplasty | Restrictive | One prospective study (64 patients) | Long-term efficacy |
| Depth of suture | |||
| Transoral gastroplasty | Restrictive | Multiple human studies (> 150 patients), multicentric RCT completed unpublished | Long-term outcomes |
| Complications | |||
| Endoscopic sleeve gastroplasty | Restrictive | Large postmarketing studies (> 200 patients), no prospective evaluation with ITT analysis | Long-term outcomesPatients selection biases |
| Endoluminal suturing device | Restrictive | Limited human study (11 patients) Universal triangulation platform |
Long-term efficacy |
| Use of stitches; transmural stitching | |||
| POSE | Restrictive | Two prospective studies (n = 161 patients) | Long-term efficacy |
| Intraprocedural drop out of patients | |||
| Aspiration therapy | Malabsorptive | 11 + 25 patients treated | Adherence to protocol |
| Parietal complications | |||
| DJBS | Malabsorptive | 12 patients investigated | Patient tolerance |
| Long-term safety and efficacy | |||
| Reversibility | |||
| Liver abscesses | |||
| Gastroduodenojejunal bypass sleeve | Restrictive & malabsorptive | 13 patients investigated | Tolerance at the level of the cuff inserted at the cardia |
| Long-term efficacy |
DJBS, duodenojejunal bypass sleeve.
Restrictive Procedures
Intragastric Balloons
The use of a fluid-filled intragastric balloon to induce weight loss in obese patients was first described in 1982. Since then, numerous intragastric balloons have been in use worldwide, and several have been withdrawn from the market. The BioEnterics Intragastric Balloon (BIB; Allergan, Irvine, CA) or ORBERA (Apollo Endosurgery, Austin, TX) has a spherical shape and larger capacity than earlier models and has been the most extensively used device. Among the more recently improved minimally invasive procedures, the intragastric balloon has been one temporary nonsurgical option that can promote weight loss in obese patients by partially filling their stomach and inducing a sense of early satiety. One of the major drawbacks of balloon implantation is weight regain after balloon removal. Two early studies help clinicians better understand what can be expected from balloon implantation.
In the first study, Mathus-Vliegen and Tytgat (2005) included patients who had participated in a randomized controlled trial (RCT) comparing a balloon with a sham for a 3-month period in an additional trial which involved 9 months of balloon treatment and follow-up for 1 year after removal. The authors excluded 8 patients who had not met the weight loss goal during the first 3 months (5 patients) or who did not tolerate the balloon (3 patients). Although there was no difference between the sham and balloon during the first 3 months, after 1 year of balloon treatment, a mean weight loss of 21.3 kg (17.1%) was achieved in all patients; 12.6 kg (9.9%) was maintained at the end of the second balloon-free year. Overall, 47% of patients sustained a 10% weight loss at the end of 2 years of follow-up. Although this study did not show an independent benefit of balloon treatment beyond diet, exercise, and behavioral therapy in the first treatment, balloon treatment for 1 year, in the patients who tolerated the treatment, resulted in substantial weight loss, a significant part of which was maintained during the first year after removal of the balloon.
The second study looked at the long-term outcome after treatment with an intragastric balloon for 6 months, with no structured weight maintenance program after balloon removal. After BIB placement, 100 consecutive morbidly obese individuals were prospectively followed; 97 patients completed the final follow-up at a mean of 4.8 years. After 6 months, 63% of patients had more than 10% baseline weight loss, whereas there were only 28% at final follow-up. At that time, 35 patients had undergone bariatric surgery, and 34 patients had no significant weight change from baseline.
Finally, a 2015 systematic review and meta-analysis performed by the American Society for Gastrointestinal Endoscopy (ASGE) Bariatric Endoscopy Task Force demonstrated that an intragastric balloon results in 25.4% of excess weight loss (EWL) and 11.3% of total weight loss 1 year after balloon insertion (6 months after balloon removal). The main side effects consisted in upper gastrointestinal (GI) complaints (abdominal pain and nausea), which were responsible for early removal in approximately 7.5 % of patients. Serious adverse events are rare, including 0.1% with GI perforation and 1.4% with balloon migration.
Different technical modifications of the fluid-filled balloons have been brought to potentially improve its efficacy, tolerance, or safety profile. Currently, however, none of these have been proven to be superior. The Spatz adjustable Balloon system (Spatz FGIA, Inc., New York, NY) has an extractable inflation tube for adjustment after initial filling either in case of intolerance or decreased efficacy. It has been associated with specific complications related to catheter impaction requiring surgical extraction. However, it is approved for 1 year implantation and, in a case-controlled study that required adjustment in 22.5% of patients, had an efficacy similar to 2 consecutive BIBs left for the same period, with a similar tolerance and safety profile ( ). The ReShape Duo (ReShape, San Clemente, CA) is the second intragastric balloon approved by the Food and Drug Administration (FDA). It consists of two separately attached filled balloons (450 mL each). In the REDUCE pivotal FDA trial (a prospective, randomized controlled pivotal trial of a dual intragastric balloon for the treatment of obesity), which enrolled 326 patients, patients treated with Duo achieved significantly more weight loss than those with diet and exercise alone (27.9% vs. 11.3% EWL). Gastric ulcerations at removal were reported in 10% of cases. In Europe, the high cost of this device limits its clinical use.
Air/gas-filled balloons have been proposed as an alternative to classic fluid-filled balloons. The Heliosphere BAG balloon (Helioscopie, Vienne, France) was reported as having a similar efficacy to the BIB, with possibly less discomfort. However, a high rate of spontaneous deflation, the absence of a marker allowing early identification of a possible rupture, and technical difficulties in its positioning have limited its routine use.
Other gas-filled balloons can be swallowed without the need for endoscopy but still require endoscopy for removal (Obalon Therapeutics, Carlsbad, CA), and some are even designed to be swallowed as a pill and inflated in the stomach, and contain a resorbable valve, which would allow spontaneous deflation and uneventful migration (Allurion Technologies, Inc., Wellesley, MA). However, the clinical data available with these techniques are currently insufficient to make any recommendation on their use.
In summary, balloon implantation may be helpful for long-term weight loss in select patients. It is a potential option for patients who are unwilling to undergo bariatric surgery or who are not suitable candidates for bariatric surgery. Balloon implantation could also be used as a temporary measure in superobese patients to induce weight loss and decrease the risk of complications associated with further bariatric surgery.
Suturing/Stapling Procedures
Another group of endoscopic procedures aims to offer a long-lasting reduction of gastric volume and decrease the distensibility of the stomach by suturing or stapling techniques. This endoluminal transoral restrictive surgery includes several techniques, the first one (EndoCinch) being performed with a device initially designed for treatment of gastroesophageal reflux disease (GERD).
Endoluminal vertical gastroplasty.
The EndoCinch suturing system (C.R. Bard, Murray Hill, NJ) was initially designed for endoscopic treatment of GERD. This system allows the placement of a series of stitches in the lower esophagus to create a pleat at the level of the lower sphincter. Although associated with encouraging early results, use of the EndoCinch for the treatment of GERD has been called into question because of the lack of retention of plications in the long term.
The device was then used to restrict the gastric cavity. The technique utilizes the deployment of seven sutures in a continuous and cross-linked fashion from the proximal fundus to the distal body. Again, despite initial encouraging results, the latest development of the device (RESTORe Suturing system [Bard/Davol, Warwick, RI]), theoretically capable of full-thickness tissue apposition, found that sutures were not durable over time, leading to a lack of effectiveness.
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