Considering the increasing worldwide number of obese and overweight patients as well as obesity-related complications, there is a need for therapies that will provide long-term weight loss. To date, standard treatments of obesity that include diets, physical activity, and pharmacology have had limited efficacy. Currently, bariatric and metabolic surgery remains the most effective method to achieve and maintain weight loss. Bariatric surgery is mainly reserved for patients with a body mass index (BMI) ≥ 40 or ≥ 30 kg/m² with comorbidities. Overall, the rate of serious complications associated with bariatric surgery is 4% and mortality rate is around 0.1% (1). However, less than 2% of eligible obese patients receive bariatric surgery. There are patients who do not want to undergo surgery or patients who are at higher surgical risk, with contraindications to surgery and/or anesthesia. In addition, some patients with obesity-related comorbidities have a BMI just below the established criteria for bariatric surgery. Moreover, certain patients such as younger people would prefer to lose weight by using non-invasive options. Thus, endoscopic bariatric therapies (EBT), especially intragastric balloons (IGBs), seem to fill the gap between medical and surgical options. Despite the advantages of IGB, such as anatomy preservation, a potentially lower risk of serious complications, and costing less than bariatric surgery, the achieved weight loss is smaller and rather temporary (2, 3). Therefore, other behavioral and pharmacological interventions are important to maintain weight loss. In this paper, we will discuss the current place of IGBs in the treatment of obesity with a particular focus on their efficacy and safety, recent US Food and Drug Administration (FDA) updates, in order to facilitate future decisions on implementing EBT for the individual patient. Other EBTs will not be discussed in this review.

Endoscopic bariatric devices are generally divided into gastric and small bowel endoscopic therapies. Gastric EBT includes devices that occupy space in the stomach (IGB), devices that remove a portion of the consumed meal (aspiration therapy), and devices that alter gastric anatomy to reduce volume and accommodation (plication, suturing) (tab. 1). Some devices have already been approved by the FDA and several more are currently under investigation (4). All health care providers should be particularly familiar with IGBs which are available worldwide. Weight loss due to IGBs mostly results from increased satiety and delayed gastric emptying.

The American Society for Metabolic and Bariatric Surgery (ASMBS) has added IGB therapy to the list of approved procedures and devices for the treatment of obesity with discussing potential situations where this therapy may be offered. In general, an IGB is indicated for patients with a BMI between 30 and 40 kg/m² who were not able to lose weight or maintain weight loss with standard noninvasive methods or who refuse to undergo permanent bariatric surgery. IGB can be considered as a bridge therapy for patients who need to lose weight before non-bariatric procedures (e.g. knee or hip replacement) (2, 5).

Currently, there are three types of IGBs having been approved by the FDA from 2015 to 2016: Orbera^TM (Orbera^TM Intragastric Balloon System, Apollo Endosurgery Inc., Austin, TX), ReShape Integrated Dual Balloon System (ReShape Medical, Inc., San Clemente, CA), and the Obalon System (Obalon Therapeutics, Inc.) (tab. 2) (6-8). In addition, the FDA approved in 2016 the AsspireAssist (Aspire Bariatric Inc., King of Prussia, PA) which removes a portion of the stomach content after eating (tab. 1) (4). The Orbera^TM and ReShape balloons were the first IGBs that received approval after the removal of the Garren-Edwards Gastric Bubble (GEB, American Edwards) in 1988 due to several reports that showed a low efficacy and high complications rate including balloon deflation causing bowel obstruction, bleeding gastric ulcers, and gastric perforation (4). The ASMBS estimated that 5,000 IGBs have been implemented since FDA approval, which represents less than 3 percent of the 216,000 bariatric surgeries performed in the United States in 2016 (6). The Orbera^TM and ReShape IGBs are placed for a maximum period of 6 months. The Obalon System is intended to remain in the stomach for 6 months from the time of placement of the first balloon. After that time, all balloons must be removed. The indication for IGB according to the instruction of the individual companies are as follows. The Orbera^TM Intragastric Balloon System is indicated for patients with a BMI of ≥ 30 and ≤ 40 kg/m² in conjunction with a long-term supervised diet and behavior modification program designed to increase the possibility of significant long-term weight loss and maintenance of that weight loss. The Orbera™ IGB is indicated for adult patients who have failed to achieve weight reduction with more conservative alternatives such as a supervised diet, exercise, and behavior modification programs (10). The ReShape Dual Balloon System is indicated in conjunction with diet and exercise for adult patients with a BMI of 30 to 40 kg/m² and 1 or more obesity-related comorbid conditions and who have failed to achieve weight reduction with diet and exercise alone. The maximum placement period for the ReShape balloon is 6 months (11). The Obalon Balloon System is indicated for temporary use to facilitate weight loss in adults with obesity (BMI of 30 to 40 kg/m²) who have failed to lose weight through diet and exercise. The system is intended to be used as an adjunct to a moderate intensity diet and behavior modification program (12).