Introduction

Obesity is the pandemic of the 21st century and is associated with considerable morbidity and mortality.¹ Management of obesity depends on body mass index (BMI) and the presence of comorbidities, including heart disease, diabetes, hypertension, dyslipidemia, osteoarthritis, and sleep apnea.² Approximately 1.6 billion adults are overweight; at least 400 million adults are obese. The World Health Organization further projects that by 2015, approximately 2.3 billion adults will be overweight, and more than 700 million will be obese. Previously considered a problem only in high-income countries, overweight and obesity are now dramatically increasing in low-income and middle-income countries, particularly in urban settings.³

The only effective therapy at the present time for morbid obesity, as defined by BMI of 40 kg/m² or more or by BMI of 35 kg/m² or more in the presence of comorbidities, is surgery.⁴ 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 1998–2004,⁵ and in terms of health care demand, morbid obesity clearly represents the pandemic of the 21st century.

Bariatric surgery for morbidly obese patients has shown significant clinical benefits. It induces and maintains satisfactory weight loss while decreasing comorbidities in the patient associated with overweight.⁶ Efficacy varies with the type of procedure, which can be divided into restrictive (lap band, vertical gastroplasty, sleeve gastrectomy), malabsorptive (biliopancreatic diversion), or a combination of both (gastric bypass). The first and second types of operations are the most frequently performed sometimes as an optional two-step procedure starting with gastric restriction. Although very effective, laparoscopic and surgical bariatric procedures have complication rates of 3% to 20% and mortality rates of 1%.⁷ Cardiopulmonary events and anastomotic leaks are the major sources of severe morbidities.

The demand in recent years for less invasive therapy for obesity led to the emergence of endoscopic technology potentially characterized by less invasiveness and fewer postprocedure complications. Endoluminal surgery, performed entirely through a natural orifice, offers the 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 at the present time and address the role of endoscopy in management of complications occurring after bariatric surgery.

Endoscopic Options for Endoluminal Primary Treatment of Obesity

Intragastric Balloon

The use of an intragastric device to induce weight loss in obese patients was first described in 1982.⁸ 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) has a spherical shape and larger capacity than earlier models and has been the most extensively studied 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.^9,¹⁰ One of the major drawbacks of balloon implantation is weight regain after balloon removal. Two more recent studies help clinicians to understand better what can be expected from balloon implantation.

In the first study, Mathus-Vliegen and Tytgat ¹¹ included patients who had participated in a randomized controlled trial comparing a balloon with a sham for a 3-month period in an additional trial including 9 months of balloon treatment and follow-up for 1 year after removal. The authors excluded eight patients who had not met the weight loss goal during the first 3 months (five patients) or who did not tolerate the balloon (three 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 could 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.¹²

These studies confirm further that balloon implantation may be helpful for long-term weight loss in a few patients. It is a potential option for patients who are unwilling to undergo bariatric surgery or are not 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.¹³

Gastric Restriction

Endoluminal Vertical Gastroplasty Using EndoCinch

The EndoCinch suturing system (C.R. Bard, Murray Hill, NJ) was initially designed for endoscopic treatment of gastroesophageal reflux disease. This system allows the placement of a series of stitches in the lower esophagus to create a pleat in the sphincter. This pleat alters the gateway between the stomach and the esophagus and potentially prevents acid from flowing out of the stomach. Although associated with encouraging early results, use of the EndoCinch for the treatment of gastroesophageal reflux disease has been called into question because of the lack of retention of plications in the long-term.¹⁴

Fogel and colleagues ¹⁵ first described the use of this technology for the treatment of obesity in 64 patients. Their technique comprised the deployment of seven sutures in a continuous and cross-linked design from the proximal fundus to the distal body. The result of the treatment is suggested to be a significant decrease in distensibility of the stomach. The procedure was performed as an ambulatory procedure, and of the 59 patients followed for 12 months, the percentage excess weight loss reported was 21% at 1 month and 58% at 12 months. Only a few patients (n = 14) underwent repeated endoscopy in the follow-up period. In 11 patients, the suture line was reported as completely or partially intact. A randomized controlled trial is ongoing in the United States to investigate this technique further. It is hoped that this trial will also provide long-term data that are relevant both clinically and anatomically.