Intragastric Balloons (Obalon, Orbera, and ReShape) for Treating Obesity
August 22, 2017 | Emerging Technology Reports
Proprietary names: BioEnterics Intragastric Balloon (BIB®), EzFill Can and Canister, Obalon®, Orbera® Intragastric Balloon System, ReShape™ Integrated Dual Balloon System (Model RSM101).
Generic names: intragastric bubble, intragastric balloon.
Obesity is defined as an excessive accumulation of body fat, resulting from a positive imbalance between caloric intake and expenditure.1-3 Body fat content is measured using body mass index (BMI). Adults are considered obese if their BMI is greater than 30 kg/m2 and severely or morbidly obese if it is greater than 40 kg/m2.1,3,4 Behavioral, environmental, and genetic factors contribute to obesity's development. Increased caloric consumption and low levels of physical activity promote weight gain and result from lifestyle choices, socioeconomic status, psychological disorders, or physical disability.5 Certain types of medication used to treat mood disorders, seizures, migraines, cardiovascular disease, hypertension, and diabetes also promote weight gain.5 Clinicians estimate that obesity is 40% to 70% inheritable, and results from a 2015 genome-wide association study suggest that common genetic variants may account for up to 21% of BMI variation.2,6
Individuals who are obese are at an increased risk of morbidity and mortality. Obesity is a major risk factor for cardiovascular disease and is associated with hyperlipidemia, hypertension, and type 2 diabetes mellitus, which are major cardiovascular risk factors. In addition, obese individuals have a greater chance of developing fatty liver disease, gallbladder disease, osteoarthritis, stroke, sleep apnea, and certain forms of cancer.7,8 A meta-analysis of 57 prospective studies that included nearly 900,000 adults suggests that overall mortality rises by 30% for every 5 kg/m2 above the ideal BMI of 25 kg/m2.9
Obesity treatments attempt to reduce obesity-related comorbidities and risks by reducing body weight. Total weight loss (TWL) as modest as 5% to 10% can significantly reduce comorbidity risks in obese individuals.10 First-line therapies combine dietary and exercise regimens, patient education, and treatment of underlying medical conditions to reverse the caloric imbalance and induce weight loss.11-13 These interventions may help some individuals reach and maintain a healthy weight; however, their overall effectiveness may be limited.14,15 On average, individuals enrolled in clinical weight- loss programs lose 7% to 10% of their weight during the first year, but many discontinue the interventions and regain most of the lost weight.16-18 Medication can complement lifestyle modification. Available drugs induce weight loss by suppressing hunger (phentermine, phentermine/topiramate, lorcaserin, liraglutide, and naltrexone/bupropion) or inhibiting lipid absorption (orlistat), typically achieving 3% to 9% TWL.2,19
The limited impact of conservative therapies has prompted investigators to explore several minimally invasive approaches to weight loss.20-22 Most of these involve endoscopic procedures and devices, such as intragastric balloons (IGBs), to restrict food intake and/or delay gastric emptying to induce satiety. Most of these devices can remain in place only temporarily, usually between 6 and 12 months.23-26 A second type of approach involves neurostimulation to modulate the neuroendocrine regulation of appetite. Vagus nerve blocking neurostimulation, introduced in the United States in 2015, is an example of this approach.21,23,27 Because of their novelty, these technologies have yet to be fully incorporated in the recommended clinical obesity treatment pathway.28,29
Clinical guidelines recommend offering bariatric surgery to patients with either a BMI >40 kg/m2, or a BMI >35 kg/m2 with one or more obesity-related comorbidities, whose condition has not improved despite attempted lifestyle modification and pharmacotherapy.5,11-13,19,22,30 Bariatric surgery involves one or both general approaches: reducing the stomach's functional volume or reducing intestine's functional length.31-34 These changes result in weight loss by limiting nutrient absorption and altering the production of gastrointestinal (GI) hormones that regulate satiety and metabolism. The most frequently practiced procedures in the United States are vertical sleeve gastrectomy, followed by Roux-en-Y gastric bypass and laparoscopic gastric banding.31-34
Patients who undergo bariatric surgery lose on average 50% to 70% of their excess weight after 1 year (10% to 40% of TBW) and regain no more than 10% of the lost weight in the following 5 to 10 years.32,35-38 Bariatric surgery is therefore effective in achieving durable weight loss; however, it is also associated with a mortality rate of 0.1% to 1% and morbidity rates of 7% to 20%.32-34 Complications include GI suture leakage, bleeding, and infection, as well as implant slippage and stomach erosion for adjustable gastric banding (Lap-Band) procedures.32-34 Patients with a BMI >50 kg/m2 and those with an enlarged, fatty liver are at increased risk of complications.39-41 Clinicians often prescribe diet, exercise, and medication regimens to these patients as a "bridge therapy" to reduce complication risks by achieving partial weight loss in the months leading to surgery.19,29-31
Despite the effectiveness of bariatric surgery, only 1% to 2% of eligible patients choose to undergo a procedure, largely because patients and physicians are wary of complications and may not perceive surgery as warranted.42,43 Clinicians and patients are therefore interested in minimally invasive interventions that are more acceptable and provide an alternative to or bridge intervention to bariatric surgery. Intragastric balloons (IGBs) are one such technology. These space-occupying devices are intended to produce weight loss by helping patients reduce their food intake.23,44-46 The first IGBs were designed in the 1980s and as of August 2016, 16 different models were available worldwide.23,44,45,47 This report focuses on the three IGBs approved by FDA for treating obesity: Obalon (Obalon Therapeutics, Inc., Carlsbad, CA, USA), Orbera (Apollo Endosurgery, Inc., Austin, TX, USA), and ReShape (ReShape Medical, Inc., San Clemente, CA, USA).48,49 FDA approved the devices in 2015 and 2016, making them available for the first time on the U.S. market.50
Based on results of the 2011-2012 National Health and Nutrition Examination Survey, the Centers for Disease Control and Prevention estimates that 34.9% (about 78.6 million people) of U.S. residents aged 20 or older are obese. The study found that overall obesity rates have not changed significantly between 2004 and 2012.51,52 More than 154,000 patients underwent bariatric or metabolic surgery in the United States and Canada in 2013, according to results of a survey by the International Federation of Obesity and Metabolic disorders (IFSO).53 A 2014 review of three U.S. patient registries spanning 2007 to 2013 found that 19% to 22% of patients undergoing bariatric surgery have BMI >50 kg/m2.54
According to the World Health Organization (WHO), the worldwide prevalence of obesity among adults (aged over 20) in 2008 was close to 13%, or about 600 million people.1 WHO estimates that obesity prevalence in 2008 is twice what it was in 1980.55 A 2013 global survey by IFSO found that more than 468,000 patients in 44 countries underwent bariatric or metabolic surgery that year.53
IGBs are round, gas- or fluid-filled silicone implants that may be placed temporarily in the stomach of patients with obesity to potentially produce weight loss by inducing satiety. These devices can remain in place for only several months at a time, as longer placement may cause erosion of the stomach walls and bowel obstruction if the balloon deflates. IGBs are intended to supplement lifestyle modification and pharmacologic interventions when these alone are insufficient to produce weight loss.39,46,56,57 Physicians may also prescribe IGB...