NOTE: This policy is used to determine coverage of bariatric surgery for members whose plan documents include this benefit. Please review the individual plan document to determine if coverage is available.

Description:
Bariatric surgery is a treatment for obesity in patients who fail to lose weight with conservative measures. There are numerous gastric and intestinal surgical techniques available. While these techniques have heterogeneous mechanisms of action, the result is a smaller gastric pouch that leads to restricted eating. However, these surgeries may lead to malabsorption of nutrients or eventually to metabolic changes.

Summary of Evidence
Adults With Class 3 Obesity
For individuals who are adults (18 years or older) with class 3 obesity (body mass index [BMI] ≥ 40kg/m2) who are treated with bariatric surgery using open or laparoscopic gastric bypass using a Roux-en-Y, laparoscopic adjustable gastric banding, open or laparoscopic sleeve gastrectomy, or open or laparoscopic biliopancreatic bypass/diversion (i.e., Scopinaro procedure) with duodenal switch, the evidence includes randomized controlled trials (RCTs), observational studies, and systematic reviews. Relevant outcomes are overall survival (OS), change in disease status, functional outcomes, health status measures, quality of life, and treatment-related mortality and morbidity. Evidence from nonrandomized comparative studies, case series, and meta-analyses of RCTs has consistently reported that bariatric surgery results in substantially greater weight loss than nonsurgical therapy. Data from the largest comparative study (the SOS study) found that bariatric surgery was associated with improvements in mortality, type 2 diabetes (T2D), cardiovascular risk factors, and quality of life. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

Adults With Class 2 Obesity
For individuals who are adults (18 years or older) with class 2 obesity (BMI ≥ 35 to 39.9 kg/m2) who are treated with bariatric surgery using open or laparoscopic gastric bypass using a Roux-en-Y, laparoscopic adjustable gastric banding, open or laparoscopic sleeve gastrectomy, or open or laparoscopic biliopancreatic bypass/diversion (i.e., Scopinaro procedure) with duodenal switch, the evidence includes RCTs, observational studies, and systematic reviews. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, quality of life, and treatment-related mortality and morbidity. Evidence from nonrandomized comparative studies, case series, and meta-analyses of RCTs has consistently reported that bariatric surgery results in substantially greater weight loss than nonsurgical therapy. Data from the largest comparative study (the SOS study) found that bariatric surgery was associated with improvements in mortality, T2D, cardiovascular risk factors, and quality of life. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

Adults With Class 1 Obesity and Type 2 Diabetes
For individuals who have Class 1 obesity (BMI ≥ 30 to 34.9 kg/m2) and T2Ded with bariatric surgery using open or laparoscopic gastric bypass using a Roux-en-Y, laparoscopic adjustable gastric banding, open or laparoscopic sleeve gastrectomy, or open or laparoscopic biliopancreatic bypass/diversion (i.e., Scopinaro procedure) with duodenal switch, the evidence includes systematic reviews of RCTs and observational studies. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, quality of life, and treatment-related mortality and morbidity. Systematic reviews of RCTs and observational studies have found that certain types of bariatric surgery are more efficacious than medical therapy as a treatment for T2D in adults with obesity, including those with a BMI between 30 and 34.9 kg/m2. The greatest amount of evidence assesses gastric bypass, with some comparative studies on laparoscopic adjustable gastric banding, laparoscopic sleeve gastrectomy, and biliopancreatic bypass/diversion. Systematic reviews have found significantly greater remission rates of diabetes, decrease in hemoglobin A1C (HbA1C) levels, and decrease in BMI with bariatric surgery than with nonsurgical treatment. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

Adults With a Body Mass Index < 35 kg/m2 Who Do Not Have Type 2 Diabetes
For individuals with a BMI < 35 kg/m2 who do not have T2D who receive bariatric surgery, the evidence includes systematic reviews of RCTs and observational studies. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, quality of life, and treatment-related mortality and morbidity. A few small RCTs and case series have reported a loss of weight and improvements in comorbidities for this population. However, the evidence does not permit conclusions on the long-term risk-benefit ratio of bariatric surgery in this population. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

Revision Bariatric Surgery
For individuals who are adults who receive revision bariatric surgery, the evidence includes systematic reviews, case series, and registry data. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, quality of life, and treatment-related mortality and morbidity. Systematic reviews and case series have shown that patients receiving revision bariatric surgery experienced satisfactory weight loss and reduced comorbidities including gastroesophageal reflux disease. Data from a multinational bariatric surgery database has found that corrective procedures following primary bariatric surgery are relatively uncommon but generally safe and efficacious. A large retrospective analysis found a serious complication rate of 7.2% for conversion to RYGB in 13,432 individuals and no difference in 30-day mortality compared to primary RYGB. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

Adolescents With Obesity
For individuals who are adolescent children with obesity who are treated with bariatric surgery using open or laparoscopic gastric bypass, laparoscopic adjustable gastric banding, or open or laparoscopic sleeve gastrectomy, the evidence includes RCTs, observational studies, and systematic reviews. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, quality of life, and treatment-related mortality and morbidity. Systematic reviews of studies on bariatric surgery in adolescents, who mainly received gastric bypass or laparoscopic adjustable gastric banding or sleeve gastrectomy, found significant weight loss and reductions in comorbidity outcomes with bariatric surgery. For bariatric surgery in the adolescent population, although data are limited on some procedures, studies have generally reported that weight loss and reduction in risk factors for adolescents are similar to that for adults. Most experts and clinical practice guidelines have recommended that bariatric surgery in adolescents be reserved for individuals with severe comorbidities, or for individuals with a BMI greater than 50 kg/m2. Also, greater consideration should be placed on the patient developmental stage, on the psychosocial aspects of obesity and surgery, and on ensuring that the patient can provide fully informed consent. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

Preadolescent Children With Obesity
For individuals who are preadolescent children with obesity who receive bariatric surgery, there are no studies focused solely on this population. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, quality of life, and treatment-related mortality and morbidity. Several studies of bariatric surgery in adolescents have also included children younger than 12 years old. A recent (2021) cohort study included 801 children ages 5 to 14 years in their total cohort of children and adolescents, and excess weight loss and comorbidity resolution were substantial and long-lasting without safety concerns across all age groups. However, comparative studies are still lacking. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

Hiatal Hernia Repair With Bariatric Surgery
For individuals with obesity and a preoperative diagnosis of a hiatal hernia who receive hiatal hernia repair with bariatric surgery, the evidence includes a systematic review, cohort studies, and case series. Relevant outcomes are OS, change in disease status, functional outcomes, health status measures, quality of life, and treatment-related mortality and morbidity. A systematic review found that hiatal hernia repair during sleeve gastrectomy was superior to sleeve gastrectomy alone for gastroesophageal reflux disease remission, but not de novo. Results from the cohort studies and case series have shown that, when a preoperative diagnosis of a hiatal hernia has been present, repairing the hiatal hernia during bariatric surgery resulted in fewer complications. However, the results are limited to individuals with a preoperative diagnosis. There was no evidence on the use of hiatal hernia repair when the hiatal hernia diagnosis is incidental. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome. 

BACKGROUND 
BARIATRIC SURGERY
Bariatric surgery is performed to treat obesity and obesity-related comorbid conditions. The first treatment of obesity is dietary and lifestyle changes. Although this strategy may be effective in some patients, only a few individuals with obesity can reduce and control weight through diet and exercise. Most patients find it difficult to comply with these lifestyle modifications on a long-term basis. When conservative measures fail, some patients may consider surgical approaches.

Regulatory Status
Forms of bariatric surgery performed without specific implantable devices are surgical procedures and, as such, are not subject to regulation by the FDA.

Table 1 shows forms of bariatric surgery with implantable devices approved by the FDA through the premarket approval process.

Table 1. FDA Approved Bariatric Surgery Devices

Device	Manufacturer	PMA Date	Labeled Indications
ObalonTM intragastric balloon system	Obalon Therapeutics Inc.	Sept 2016	For use in obese adults (BMI, 30 to 40 kg/m2) who have failed weight reduction with diet and exercise, and have no contraindications. Maximum placement time is 6 mo. Balloon is encased in a capsule. The capsule is swallowed and begins to dissolve after exposure to fluids in the stomach. After verification of capsule placement in the stomach, the balloon is filled with a gas mixture. Up to 3 balloons can be used during the 6 mo treatment period.
AspireAssist System®	Aspire Bariatrics	Jun 2016	For long-term use in conjunction with lifestyle therapy and continuous medical monitoring in obese adults > 22 y, with a BMI of 35.0 to 55.0 kg/m2 and no contraindications to the procedure who have failed to achieve and maintain weight loss with nonsurgical weight loss therapy.
ORBERA® intragastric balloon system	Apollo Endosurgery	Aug 2015	For use in obese adults (BMI, 30 to 40 kg/m2) who have failed weight reduction with diet and exercise, and have no contraindications. Maximum placement time is 6 mo. Balloon placed endoscopically and inflated with saline.
LAP-BAND Adjustable Gastric Banding System	Apollo Endosurgery (original applicant: Allergan)	Apr 2010	For use in weight reduction for severely obese adults with BMI of at least 40 kg/m2 or a BMI of at least 30 kg/m2 with ≥ 1 severe comorbid conditions who have failed more conservative weight-reduction alternatives (e.g., supervised diet, exercise, behavior modification programs).
REALIZE Adjustable Gastric Band	Ethicon Endosurgery	Nov 2007	For use in weight reduction for morbidly obese patients and for individuals with BMI of at least 40 kg/m2, or a BMI of at least 35 kg/m2 with ≥ 1 comorbid conditions, or those who are ≥ 45.4 kg over their estimated ideal weight. Indicated for use only in morbidly obese adults who have failed more conservative weight-reduction alternatives (e.g., supervised diet, exercise, behavior modification programs).

BMI: body mass index: FDA: U.S. Food and Drug Administration; PMA: premarket approval.

In February 2017, the FDA issued a letter to health care providers discussing the potential risks with liquid-filled intragastric balloons in response to reports of 2 types of adverse events related to the balloons. Several dozen reports concerned spontaneous overinflation of the balloons, which caused pain, swelling, and vomiting. The second set of adverse event reports indicated that acute pancreatitis developed in several patients due to compression of gastrointestinal structures. These reports involved both ReShape (no longer marketed in the U.S.) and ORBERA brands. The adverse events may require premature removal of the balloons.

In August 2017, the FDA issued a second letter to health care providers informing them of 5 unanticipated deaths occurring from 2016 through the time of the letter, due to intragastric balloons. The FDA recommended close monitoring of patients receiving these devices. In June 2018, the FDA reported that, since 2016, a total of 12 deaths occurred in patients with liquid-filled intragastric balloons worldwide; 7 of these deaths were in patients in the U.S.

In April 2020, the FDA provided an update on risks and continued to recommend that healthcare providers "instruct patients about the symptoms of life-threatening complications such as balloon deflation, gastrointestinal obstruction, and gastric and esophageal perforation and monitor patients closely during the entire duration of treatment for potential complications, including acute pancreatitis, spontaneous hyperinflation, and other potentially life-threatening complications."

Related Policies
20138 — Transesophageal Endoscopic Therapies for Gastroesophageal Reflux Disease
70173 — Gastric Electrical Stimulation

Policy:
Bariatric Surgery in Adults With Class 3 Obesity (BMI ≥ 40 kg/m2)
The following bariatric surgery procedures may be considered MEDICALLY NECESSARY for the treatment of class 3 obesity (BMI ≥ 40.0 kg/m2) in adults (ages 18 and older) who have failed weight loss by conservative measures:

• Open or laparoscopic gastric bypass using a Roux-en-Y,
• Open or laparoscopic sleeve gastrectomy (SG), and
• Open or laparoscopic biliopancreatic bypass/diversion (i.e., Scopinaro procedure) with duodenal switch (DS).

Bariatric Surgery in Adults With Class 2 Obesity (BMI ≥ 35 to 39.9 kg/m2)
The following bariatric surgery procedures may be considered MEDICALLY NECESSARY for the treatment of class 2 obesity in individuals with at least 1 obesity-related comorbid condition (see Policy Guidelines) who have failed weight loss by conservative measures:

• Open or laparoscopic gastric bypass using a Roux-en-Y,
• Open or laparoscopic sleeve gastrectomy (SG), and
• Open or laparoscopic biliopancreatic bypass/diversion (i.e., Scopinaro procedure) with duodenal switch (DS).

Bariatric surgery should be performed in appropriately selected individuals, by surgeons who are adequately trained and experienced in the specific techniques used, and in institutions that support a comprehensive bariatric surgery program, including long-term monitoring and follow-up postsurgery. (see Policy Guidelines for bariatric surgery selection criteria).

Bariatric Surgery in Individuals With Class 1 Obesity (BMI ≥ 30 to 34.9 kg/m2) and Type 2 Diabetes
For individuals with Class 1 obesity (BMI ≥ 30 to 34.9 kg/m2) and Type 2 diabetes, the following bariatric surgery procedures may be considered MEDICALLY NECESSARY in adults who have failed weight loss by conservative measures:

• Open or laparoscopic gastric bypass using a Roux-en-Y,
• Open or laparoscopic sleeve gastrectomy (SG), and
• Open or laparoscopic biliopancreatic bypass/diversion (i.e., Scopinaro procedure) with duodenal switch (DS).

Bariatric surgery is considered investigational/unproven therefore considered NOT MEDICALLY NECESSARY for individuals with Class 1 obesity who do not have Type 2 diabetes.

Bariatric surgery is considered investigational/unproven therefore considered NOT MEDICALLY NECESSARY for individuals with a BMI less than 30 kg/m2.

The following bariatric surgery procedures are considered investigational for the treatment of obesity:

• Vertical-banded gastroplasty,
• Gastric bypass using a Billroth II type of (mini-gastric bypass),
• Biliopancreatic diversion (BPD) without DS,
• Long-limb gastric bypass procedure (i.e., > 150 cm),
• Two-stage bariatric surgery procedures (e.g., SG as initial procedure followed by BPD at a later time),
• Laparoscopic gastric plication, and
• Single anastomosis duodeno-ileal bypass with SG.
• Laparoscopic adjustable gastric banding.

Revision Bariatric Surgery
Revision surgery to address perioperative or late complications of the original bariatric procedure may be considered MEDICALLY NECESSARY. They include, but are not limited to, staple-line failure, obstruction, stricture, non-absorption resulting in hypoglycemia or malnutrition, weight loss of 20% or more below ideal body weight, and band slippage that cannot be corrected with manipulation or adjustment (see Policy Guidelines section).

Revision of a primary bariatric procedure that has failed due to dilation of the gastric pouch or dilation proximal to an adjustable gastric band (documented by upper gastrointestinal examination or endoscopy) is considered MEDICALLY NECESSARY if the initial procedure was successful in inducing weight loss prior to pouch dilation, and the patient has been compliant with a prescribed nutrition and exercise program. Converting from one surgical intervention to a second, particularly because the desired weight loss has not been realized, is considered a second procedure and not a revision and is subject to the limitation of one procedure per lifetime. 

REVISION BARIATRIC SURGERY FOR MEDICALLY REFRACTORY REFLUX 
Revision bariatric surgery for the treatment of Medically Refractory Reflux may be considered medically necessary when ALL of the following criteria are met:  

1. Independent Gastroenterology evaluation determines that revision surgery is the appropriate treatment to manage medically refractory reflux. 
2. A minimum of 8-weeks optimal with either PPI therapy prescribed twice daily, OR Dexilant prescribed once daily in combination with H2 Blocker (Pepcid).  
3. Additional treatment with an adjunctive topical agent (i.e. Carafate) 
4. Objective imaging or diagnostic studies after the 8-week medical treatment 
   1. EGD showing erosive disease (Grade C or D), esophageal stricture, peptic ulcer disease, or Barrett’s Esophagus, OR 
   2. pH impedance study with elevated acid exposure time or reflux burden 

Bariatric Surgery in Adolescents
Bariatric surgery in adolescents may be considered MEDICALLY NECESSARY according to similar weight-based criteria used for adults, but greater consideration should be given to psychosocial and informed consent issues (see Policy Guidelines section). In addition, any devices used for bariatric surgery must be used in accordance with the U.S. Food and Drug Administration approved indications.

Bariatric Surgery in Preadolescent Children
Bariatric surgery is investigational/unproven therefore considered NOT MEDICALLY NECESSARY for the treatment of obesity in preadolescent children.

Concomitant Hiatal Hernia Repair With Bariatric Surgery
Repair of a hiatal hernia at the time of bariatric surgery may be considered MEDICALLY NECESSARY for individuals who have a preoperatively diagnosed hiatal hernia with indications for surgical repair (see Policy Guidelines section).

Repair of a hiatal hernia that is diagnosed at the time of bariatric surgery, or repair of a preoperatively diagnosed hiatal hernia in individuals who do not have indications for surgical repair is investigational/unproven therefore considered NOT MEDICALLY NECESSARY.

Endoscopic Procedures
The following endoscopic procedures are investigational/unproven therefore considered NOT MEDICALLY NECESSARY as a primary bariatric procedure or as a revision procedure (i.e., to treat weight gain after bariatric surgery to remedy large gastric stoma or large gastric pouches):

• Insertion of the StomaphyX™ device,
• Endoscopic gastroplasty,
• Use of an endoscopically placed duodenojejunal sleeve,
• Intragastric balloons, and
• Aspiration therapy device.
• TORe (trans oral outlet reduction)

Policy Guidelines:
Weight-Related Complications
Clinical Practice Guidelines list the following conditions weight-related complications, defined as conditions caused by or exacerbated by excess adiposity:¹

• Asthma
• Cardiovascular disease
• Certain types of cancer (e.g., colorectal cancer)
• Type 2 diabetes
• Dyslipidemia
• Gastroesophageal reflux disease (GERD)
• Hypertension
• Infertility
• Male hypogonadism
• Mental health (depression)
• Metabolic syndrome
• Nonalcoholic fatty liver disease (nonalcoholic fatty liver and nonalcoholic steatohepatitis)
• Obstructive sleep apnea
• Osteoarthritis
• Polycystic ovarian syndrome
• Prediabetes
• Stroke
• Urinary stress incontinence

Recommendations specify that bariatric surgery may be considered in individuals with a body mass index (BMI) of ≥ 35 kg/m2 and 1 or more severe obesity-related complications, including Type 2 diabetes, hypertension, obstructive sleep apnea, obesity-hypoventilation syndrome, Pickwickian syndrome, nonalcoholic fatty liver disease or nonalcoholic steatohepatitis, pseudotumor cerebri, GERD, asthma, venous stasis disease, severe urinary incontinence, debilitating arthritis, or considerably impaired quality of life.¹ Guidelines do not explicitly define thresholds for determining the clinical significance of obesity-related conditions that would qualify individuals for bariatric surgery, however.

Bariatric Surgery Selection Criteria
Patients should have documented failure to respond to conservative measures for weight reduction prior to consideration of bariatric surgery, and these attempts should be reviewed by the practitioner prior to seeking approval for the surgical procedure. As a result, some centers require active participation in a formal weight reduction program that includes frequent documentation of weight, dietary regimen, and exercise. However, there is a lack of evidence on the optimal timing, intensity, and duration of nonsurgical attempts at weight loss, and whether a medical weight loss program immediately preceding surgery improves outcomes.

Patients with a BMI of 50 kg/m2 or more need a bariatric procedure to achieve greater weight loss. Thus, the use of adjustable gastric banding, which results in less weight loss, should be most useful as a procedure for patients with a BMI less than 50 kg/m2. Malabsorptive procedures, although they produce more dramatic weight loss, potentially result in nutritional complications, and the risks and benefits of these procedures must be carefully weighed in light of the treatment goals for each patient. Patients who undergo adjustable gastric banding and fail to achieve adequate weight loss must show evidence of postoperative compliance with diet and regular bariatric visits prior to consideration of a second bariatric procedure.

Considerations for Bariatric Surgery in Adolescents
Guidelines for bariatric surgery in adolescents are not uniform, with variability in weight-based criteria, ranging from a BMI of 35 kg/m2 with comorbidities to a BMI of 50 kg/m2. Most guidelines use weight-based criteria that parallel those for adults.

In addition to the weight-based criteria, there is greater emphasis on issues of developmental maturity, psychosocial status, and informed consent for adolescent patients. All guidelines mention these issues, but recommendations are not uniform The following are examples from U.S. guidelines published since 2013 that address issues of maturity and psychosocial status.

Endocrine Society

• The child has attained Tanner 4 or 5 pubertal development and final or near-final adult height.
• Psychological evaluation confirms the stability and competence of the family unit.
• The patient demonstrates the ability to adhere to the principles of healthy dietary and activity habits (Styne et al., 2017).

Bariatric Procedure Selection for Adolescents
The choice of procedure in adolescents may also differ from adults, but there is a lack of consensus in guidelines or expert opinion as to the preferred procedure(s) for adolescents. The following factors should be considered in the choice of bariatric surgery in adolescents (Aikenhead et al., 2011; PMID: 25586970):

• As in adults, laparoscopic gastric bypass is the most common procedure in adolescents.
• Devices used for laparoscopic adjustable gastric band (LAGB) do not have FDA approval in the United States for individuals younger than age 18 years.
• Some guidelines for bariatric surgery in adolescents do not recommend biliopancreatic diversions (BPD) because of the greater frequency of nutritional deficiencies on long-term follow-up, but other guidelines do not specify that BPD not be done in adolescents.

In 2018, the American Society for Metabolic and Bariatric Surgery (ASMBS) published an updated guideline on pediatric metabolic and bariatric surgery (Pratt et al., 2018). With regard to choice of procedure, the guideline stated:

• "Vertical sleeve gastrectomy has become the most used and most recommended operation in adolescents with severe obesity for several reasons, near-equivalent weight loss to RYGB [Roux-en-Y gastric bypass] in adolescents, fewer reoperations, better iron absorption, and near-equivalent effect on comorbidities as RYGB in adolescents. However, given the more extensive long-term data available for RYGB, we can recommend the use of either RYGB or VSG in adolescents."

Hiatal Hernia Repair Guidelines
In 2018, the ASMBS and the American Hernia Society published a consensus guideline on bariatric surgery and hernia surgery (Menzo et al., 2018). The guideline contained the following conclusions and summary recommendations:

• "There is a significant link between obesity and hernia formation both after abdominal surgery and de novo. There is also evidence that abdominal wall hernia can more commonly present with obstruction or strangulation in patients with obesity."
• "There is a higher risk for complications and recurrence after hernia repair in patients with obesity."
• "In patients with severe obesity and ventral hernia, and both being amenable to laparoscopic repair, combined hernia repair and metabolic/bariatric surgery may be safe and associated with good short-term outcomes and low risk of infection. There is a relative lack of evidence, however, about the use of synthetic mesh in this setting."
• "In patients with severe obesity and abdominal wall hernia that is not amenable to laparoscopic repair, a staged approach is recommended. Weight loss prior to hernia repair is likely to improve hernia repair outcomes. Metabolic/bariatric surgery appears to provide far more significant and rapid weight loss than other modalities and would be a good option for selected patients with severe obesity and large, symptomatic abdominal wall hernia."

The Society of American Gastrointestinal and Endoscopic Surgeons issued evidence-based guidelines for the management of hiatal hernia (Kohn et al., 2013). The Society noted that the general methodologic quality of available studies is low. Recommendations for indications for repair are as follows:

• “Repair of a type I hernia [sliding hiatal hernias, where the gastroesophageal junction migrates above the diaphragm] in the absence of reflux disease is not necessary” (moderate-quality evidence, strong recommendation).
• “All symptomatic paraesophageal hiatal hernias should be repaired [high-quality evidence, strong recommendation], particularly those with acute obstructive symptoms or which have undergone volvulus.”
• “Routine elective repair of completely asymptomatic paraesophageal hernias may not always be indicated. Consideration for surgery should include the patient’s age and co-morbidities” (moderate-quality evidence, weak recommendation).

Coding
See the Codes table for details..

Benefit Application
State mandates and contractual exclusions may apply to coverage eligibility of bariatric surgery in general.

State or federal mandates (e.g., Federal Employee Program) may dictate that certain U.S. Food and Drug Administration-approved devices, drugs, or biologics may not be considered investigational, and thus these devices may be assessed only by their medical necessity.

State or federal mandates (e.g., FEP) may dictate that all devices approved by the U.S. Food and Drug Administration (FDA) (i.e., the Lap-Band device) may not be considered investigational, and thus coverage eligibility of these devices may be assessed only on the basis of their medical necessity.

Rationale
This evidence review was created in July 1996 and has been updated regularly with searches of the PubMed database. The most recent literature update was performed through March 7, 2024.

Evidence reviews assess the clinical evidence to determine whether the use of technology improves the net health outcome. Broadly defined, health outcomes are the length of life, quality of life, and ability to function including benefits and harms. Every clinical condition has specific outcomes that are important to patients and managing the course of that condition. Validated outcome measures are necessary to ascertain whether a condition improves or worsens; and whether the magnitude of that change is clinically significant. The net health outcome is a balance of benefits and harms.

To assess whether the evidence is sufficient to draw conclusions about the net health outcome of technology, 2 domains are examined: the relevance, and quality and credibility. To be relevant, studies must represent 1 or more intended clinical use of the technology in the intended population and compare an effective and appropriate alternative at a comparable intensity. For some conditions, the alternative will be supportive care or surveillance. The quality and credibility of the evidence depend on study design and conduct, minimizing bias and confounding that can generate incorrect findings. The randomized controlled trial (RCT) is preferred to assess efficacy; however, in some circumstances, nonrandomized studies may be adequate. RCTs are rarely large enough or long enough to capture less common adverse events and long-term effects. Other types of studies can be used for these purposes and to assess generalizability to broader clinical populations and settings of clinical practice.

Promotion of greater diversity and inclusion in clinical research of historically marginalized groups (e.g., people of color [African American, Asian, Black, Latino and Native American]; LGBTQIA [lesbian, gay, bisexual, transgender, queer, intersex, asexual]; women; and people with disabilities [physical and invisible]) allows policy populations to be more reflective of and findings more applicable to our diverse members. While we also strive to use inclusive language related to these groups in our policies, use of gender-specific nouns (e.g., women, men, sisters, etc.) will continue when reflective of language used in publications describing study populations.

Bariatric Surgery in Adults With Obesity
Clinical Context and Therapy Purpose
The following PICO was used to select literature to inform this review.

Populations
The relevant population of interest is adults with a diagnosis of obesity.

Diagnosis is based on body mass index (BMI) plus clinical judgment. Clinicians are advised to consider age, gender, ethnicity, fluid status, and muscularity when evaluating individuals for weight management. Classification of overweight and obesity and associated risk of comorbidities is shown in Table 2. Lower BMI threshold recommended in South Asian, Southeast Asian, and East Asian adult populations.2,

Table 2. Overweight and Obesity Classification

Classification	Body Mass Index (kg/m2)	Comorbidity Risk
Overweight	25.0 – 29.9	Increased
Class 1 obesity	30 – 34.9	Moderate
Class 2 obesity	35 – 39.9	Severe
Class 3 obesity	≥ 0	Very severe

Weight-related comorbidities are conditions caused by or exacerbated by excess weight. Clinical practice guidelines include a wide range of these conditions:

• Asthma
• Cardiovascular disease
• Certain types of cancer (e.g., colorectal cancer)
• Type 2 diabetes
• Dyslipidemia
• GERD
• Hypertension
• Infertility
• Male hypogonadism
• Mental health (depression)
• Metabolic syndrome
• Nonalcoholic fatty liver disease (nonalcoholic fatty liver and nonalcoholic steatohepatitis)
• Obstructive sleep apnea
• Osteoarthritis
• Polycystic ovarian syndrome
• Prediabetes
• Stroke
• Urinary stress incontinence

Interventions
The therapy being considered is any bariatric surgery procedure.

Open Gastric Bypass
The original gastric bypass surgeries were based on the observation that postgastrectomy patients tended to lose weight. The current procedure (CPT code 43846) involves both a restrictive and a malabsorptive component, with the horizontal or vertical partition of the stomach performed in association with a Roux-en-Y procedure (i.e., gastrojejunal). Thus, the flow of food bypasses the duodenum and proximal small bowel. The procedure may also be associated with an unpleasant “dumping syndrome,” in which a large osmotic load delivered directly to the jejunum from the stomach produces abdominal pain and/or vomiting. The dumping syndrome may further reduce intake, particularly in “sweets eaters.” Surgical complications include leakage and operative margin ulceration at the anastomotic site. Because the normal flow of food is disrupted, there are more metabolic complications than with other gastric restrictive procedures, including iron deficiency anemia, vitamin B12 deficiency, and hypocalcemia, all of which can be corrected by oral supplementation. Another concern is the ability to evaluate the “blind” bypassed portion of the stomach. Gastric bypass may be performed with either an open or laparoscopic technique.

Note: In 2005, CPT code 43846 was revised to indicate that the short limb must be 150 cm or less, compared with the previous 100 cm. This change reflects the common practice in which the alimentary (i.e., jejunal limb) of a gastric bypass has been lengthened to 150 cm. This length also serves to distinguish a standard gastric bypass with a very long, or very, very long gastric bypass, as discussed further here.

Laparoscopic Gastric Bypass
CPT code 43644 was introduced in 2005 and described the same procedure as open gastric bypass (CPT code 43846), but performed laparoscopically.

Laparoscopic Adjustable Gastric Banding
Adjustable gastric banding (CPT code 43770) involves placing a gastric band around the exterior of the stomach. The band is attached to a reservoir implanted subcutaneously in the rectus sheath. Injecting the reservoir with saline will alter the diameter of the gastric band; therefore, the rate-limiting stoma in the stomach can be progressively narrowed to induce greater weight loss, or expanded if complications develop. Because the stomach is not entered, the surgery and any revisions, if necessary, are relatively simple.

Complications include slippage of the external band or band erosion through the gastric wall. Adjustable gastric banding has been widely used in Europe. Two banding devices are approved by the U.S. Food and Drug Administration (FDA) for marketing in the United States. The first to receive the FDA approval was the LAP-BAND^® (original applicant, Allergan, BioEnterics, Carpinteria, CA; now Apollo Endosurgery, Austin, TX). The labeled indications for this device are as follows:

"The LAP-BAND system is indicated for use in weight reduction for severely obese patients with a BMI of at least 40 or a BMI of at least 35 with 1 or more severe comorbid conditions, or those who are 100 lb or more over their estimated ideal weight according to the 1983 Metropolitan Life Insurance Tables (use the midpoint for medium frame). It is indicated for use only in severely obese adult patients who have failed more conservative weight-reduction alternatives, such as supervised diet, exercise, and behavior modification programs. Patients who elect to have this surgery must make the commitment to accept significant changes in their eating habits for the rest of their lives."

In 2011, the FDA-labeled indications for LAP-BAND were expanded to include patients with a BMI from 30 to 34 kg/m2 with at least 1 obesity-related comorbid condition.

The second adjustable gastric banding device approved by the FDA through the premarket approval process is the REALIZE^® model (Ethicon Endo-Surgery, Cincinnati, OH). Labeled indications for this device are:

“The [REALIZE] device is indicated for weight reduction for morbidly obese patients and is indicated for individuals with a BMI of at least 40 kg/m2, or a BMI of at least 35 kg/m2 with 1 or more comorbid conditions. The Band is indicated for use only in morbidly obese adult patients who have failed more conservative weight-reduction alternatives, such as supervised diet, exercise, and behavior modification programs.”

Open or Laparoscopic Sleeve Gastrectomy
A sleeve gastrectomy (SG; CPT code 43775) is an alternative approach to gastrectomy that can be performed on its own or in combination with malabsorptive procedures (most commonly biliopancreatic diversion [BPD] with duodenal switch [DS]). In this procedure, the greater curvature of the stomach is resected from the angle of His to the distal antrum, resulting in a stomach remnant shaped like a tube or sleeve. The pyloric sphincter is preserved, resulting in a more physiologic transit of food from the stomach to the duodenum and avoiding the dumping syndrome (overly rapid transport of food through the stomach into intestines) seen with distal gastrectomy. This procedure is relatively simple to perform and can be done as an open or laparoscopic procedure. Some surgeons have proposed the SG as the first in a 2-stage procedure for very high-risk patients. Weight loss following SG may improve a patient’s overall medical status and, thus, reduce the risk of a subsequent more extensive malabsorptive procedure (e.g., BPD).

Open or Laparoscopic Biliopancreatic Diversion
The BPD procedure (also known as the Scopinaro procedure; CPT code 43847), developed and used extensively in Italy, was designed to address drawbacks of the original intestinal bypass procedures that have been abandoned due to unacceptable metabolic complications. Many complications were thought to be related to bacterial overgrowth and toxin production in the blind, bypassed segment. In contrast, BPD consists of a subtotal gastrectomy and diversion of the biliopancreatic juices into the distal ileum by a long Roux-en-Y procedure. The procedure consists of the following components:

• A distal gastrectomy induces temporary early satiety and/or the dumping syndrome in the early postoperative period, both of which limit food intake.
• A 200-cm long “alimentary tract” consists of 200 cm of ileum connecting the stomach to a common distal segment.
• A 300- to 400-cm “biliary tract” connects the duodenum, jejunum, and remaining ileum to the common distal segment.
• A 50- to 100-cm “common tract” is where food from the alimentary tract mixes with biliopancreatic juices from the biliary tract. Food digestion and absorption, particularly of fats and starches, are therefore limited to this small segment of bowel, creating selective malabsorption. The length of the common segment will influence the degree of malabsorption.

Because of the high incidence of cholelithiasis associated with the procedure, patients typically undergo an associated cholecystectomy.

Many potential metabolic complications are related to BPD, including, most prominently, iron deficiency anemia, protein malnutrition, hypocalcemia, and bone demineralization. Protein malnutrition may require treatment with total parenteral nutrition. Also, several case reports have noted liver failure resulting in death or liver transplant.

Open or Laparoscopic Biliopancreatic Diversion With Duodenal Switch
CPT code 43845, which specifically identifies the duodenal switch (DS) procedure, was introduced in 2005. The DS procedure is a variant of the BPD previously described. In this procedure, instead of performing a distal gastrectomy, a SG is performed along the vertical axis of the stomach. This approach preserves the pylorus and initial segment of the duodenum, which is then anastomosed to a segment of the ileum, similar to the BPD, to create the alimentary limb. Preservation of the pyloric sphincter is intended to ameliorate the dumping syndrome and decrease the incidence of ulcers at the duodeno-ileal by providing a more physiologic transfer of stomach contents to the duodenum. The SG also decreases the volume of the stomach and decreases the parietal cell mass. However, the basic principle of the procedure is similar to that of the BPD, i.e., producing selective malabsorption by limiting the food digestion and absorption to a short common ileal segment.

Vertical-Banded Gastroplasty
Vertical-banded gastroplasty (VBG; CPT code 43842) was formerly 1 of the most common gastric restrictive procedures performed in the United States but has now been replaced by other restrictive procedures due to high rates of revisions and reoperations. In this procedure, the stomach is segmented along its vertical axis. In order to create a durable reinforced and rate-limiting stoma at the distal end of the pouch, a plug of the stomach is removed, and a propylene collar is placed through this hole and then stapled to itself. Because the normal flow of food is preserved, metabolic complications are uncommon. Complications include esophageal reflux, dilation, or obstruction of the stoma, with the latter 2 requiring reoperation. Dilation of the stoma is a common reason for weight regain. Vertical-banded gastroplasty may be performed using an open or laparoscopic approach.

Vertical-banded gastroplasty (VBG) is a purely restrictive procedure that is largely not performed in the U.S. and has been replaced by laparoscopic adjustable gastric banding (LAGB) or sleeve gastrectomy (SG). Weight loss with VBG is substantial, but there are high rates of revisions and reoperations due to staple line disruption, perforation, band erosion or disruption, and stenosis at the band site. Overall rates of revisions and reoperations at up to 10 years may be as high as 50% (Balsiger et al., 2000, PMID11307094; Miller et al., 2007, PMID17116427). Vertical-banded gastroplasty is not included on the list of endorsed procedures by the American Society for Metabolic and Bariatric Surgery (https://asmbs.org/resources/endorsed-procedures-and-devices. Accessed Jan. 3, 2024).

Long-Limb Gastric Bypass
Variations of gastric bypass procedures have been described, consisting primarily of long-limb Roux-en-Y procedures (CPT code 43847), which vary in the length of the alimentary and common limbs. For example, the stomach may be divided with a long segment of the jejunum (instead of ileum) anastomosed to the proximal gastric stump, creating the alimentary limb. The remaining pancreaticobiliary limb, consisting of stomach remnant, duodenum, and length of proximal jejunum, is then anastomosed to the ileum, creating a common limb of variable length in which the ingested food mixes with the pancreaticobiliary juices. While the long alimentary limb permits absorption of most nutrients, the short common limb primarily limits absorption of fats. The stomach may be bypassed in a variety of ways (e.g., resection or stapling along the horizontal or vertical axis). Unlike the traditional gastric bypass, which is a gastric restrictive procedure, these very long-limb Roux-en-Y gastric bypasses combine gastric restriction with some element of malabsorptive procedure, depending on the location of the anastomoses. Note that CPT code for gastric bypass (43846) explicitly describes a short limb (< 150 cm) Roux-en-Y gastroenterostomy and, thus, would not apply to long-limb gastric bypass.

Laparoscopic Malabsorptive Procedure
CPT code 43645 was introduced in 2005, to specifically describe a laparoscopic malabsorptive procedure. However, the code does not specifically describe any specific malabsorptive procedure.

Laparoscopic Gastric Plication Laparoscopic gastric plication is a bariatric procedure that involves laparoscopic placement of sutures over the greater curvature (laparoscopic greater curvature plication) or anterior gastric region (laparoscopic anterior curvature plication) to create a tube-like stomach. To achieve gastric restriction the procedure requires 2 main steps, mobilization of the greater curvature of the stomach and suture plication of the stomach. CPT code 43843 Gastric restrictive procedure, without gastric bypass, for morbid obesity; other than vertical-banded gastroplasty is commonly used for this procedure.

Comparators
Clinical practice guidelines recommend that comprehensive lifestyle intervention (CLI; i.e., interventions that combine behavioral, dietary, and physical activity components together, should always be provided in conjunction with other weight loss interventions). VA guidelines note that although there is insufficient evidence to recommend a specific number of sessions, most CLIs offer at least 12 intervention sessions in the first 12 months of intervention.

Outcomes
The general outcomes of interest are OS, change in disease status, functional outcomes, health status measures, quality of life, treatment-related mortality, and treatment-related morbidity.

Percent weight lost (e.g, proportions achieving 5%, 10%, and 15% weight loss or mean difference between groups) is commonly used in studies of interventions. Decrease in BMI can be used, especially if change leads to a change in risk category.

Recommended primary outcome measures are summarized in Table 3.

Table 3. Primary Outcome Measures for Bariatric Surgery Procedures

Outcome	Measures	Clinically Important Difference	Duration of Follow Up
Weight loss	% TBWL	•5% •FDA: varies (2% to 5%) depending on indication sought (weight loss, limited weight loss, or weight management) •Should be appropriate for associated risk •AACE: for tertiary prevention, based on comorbidities	12 months (6 months if indication is short-term weight loss)
	Responder rate	Proportion achieving at least 5% TBWL •Devices guidance - at least 50% of treated participants •Drugs guidance - at least 35% and double the control group	12 months
Adverse events	Incidence, severity	•Intervention-specific	12 months or longer

AACE: American Association of Clinical Endocrinology; FDA: Food and Drug Administration; TBWL: total body weight loss.

Indirect evidence of the effectiveness of weight loss interventions on health outcomes is provided by studies of the strength of the association between weight loss and health outcomes. AACE (2016) guidelines include a table of weight loss targets for clinical outcomes.¹

Direct evidence would come from studies of the effect of the intervention on health outcomes, preferably from randomized controlled trials.

The following secondary outcomes are of interest:

• Percent excess weight loss;
• Change in weight;
• Change in BMI (especially if decrease results in a change to a different risk group);
• Change in waist circumference;
• Patient-reported outcomes and patient preference information;
• Changes in weight-related comorbidities;

The existing literature evaluating any bariatric surgery procedure has varying lengths of follow-up, ranging from 1 to 3 years. While studies described below all reported at least 1 outcome of interest, longer follow-up was necessary to fully observe outcomes. One-year follow-up is necessary to demonstrate weight loss efficacy. Longer follow-up to 5 to 10 years is desirable to assess maintenance of weight loss, impact on co-occurring conditions, and appearance of long-term complications.

Study Selection Criteria
Methodologically credible studies were selected using the following principles:

• To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs.
• In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.
• To assess longer term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.
• Consistent with a "best available evidence approach," within each category of study design, studies with larger sample sizes and longer durations were sought.
• Studies with duplicative or overlapping populations were excluded.

Review of Evidence
Systematic Reviews
Numerous systematic reviews have compared the efficacy of bariatric surgery with conservative therapy or compared different types of bariatric surgery techniques.^3,4,5,6 Trials included in select systematic reviews can be compared in Appendix Table A1.

Many systematic reviews have reported improvements in specific obesity-related comorbidities following bariatric surgery. These reviews have relied primarily on the results of observational studies and included the outcomes of hypertension, Type 2 diabetes (T2D), hyperlipidemia, cardiovascular events, quality of life, cancer, knee pain, and liver disease.^{7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26}

Nonrandomized Studies
Swedish Obese Subjects Trial
The Swedish Obese Subjects (SOS) trial is the most influential study of bariatric surgery versus conservative treatment. The SOS trial started in 1987 with a registry containing a detailed questionnaire and clinical data on obese patients with a BMI greater than 34 kg/m2 at 480 primary health care centers in Sweden. From this registry, patients who met eligibility criteria were recruited and offered bariatric surgery. Thus, SOS patients self-selected into treatment, and there were baseline differences between groups, primarily reflecting more excess weight and a higher incidence of comorbidities in the surgery group. A total of 2010 people chose surgery, and 2037 people chose conservative care. Each surgical patient was matched on 18 clinical variables with a patient from the registry who received nonsurgical treatment (usual care). Each surgeon chose the surgical procedure offered. Most procedures were vertical-banded gastroplasty (VBG; > 70%), with gastric bypass (6%) and gastric banding (23%) procedures performed as well. Usual care in the SOS trial was the local practice of the primary care center and usually did not include pharmacologic treatment. Patients were followed at regular intervals with repeat questionnaires and physical examinations for at least 10 years.

Many publications from this trial have reported on methods, weight loss, and clinical outcomes.^27,28,29,30 The following general conclusions can be drawn from the SOS study:

• Weight loss was greater with bariatric surgery than with conservative treatment. At 10 years of follow-up, weight loss in the surgery group was 16% of total body weight compared with a weight gain of 1.6% in the conservative treatment group.
• There was significant improvement in glucose control for diabetics and reduced incidence of new cases of diabetes.
• The effect on other cardiovascular risk factors (e.g., hypertension, lipidemia) was also positive, but less marked than that seen for diabetes.
• Mortality was reduced by 29% after a mean follow-up of 10.9 years.
• Quality of life improved in the 2- to 10-year follow-up period, with the degree of improvement in quality of life correlating with the amount of weight loss.

Longitudinal Assessment of Bariatric Surgery Consortium
The Longitudinal Assessment of Bariatric Surgery Consortium study is a large prospective, longitudinal, noncomparative study of patients who underwent Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB) with follow-up through 3 years post-procedure.³¹ The study enrolled 2458 subjects, with a median BMI of 45.9 kg/m2 (interquartile range [IQR], 41.7 to 51.5 kg/m2). For their first bariatric surgical procedure, 1,738 participants underwent RYGB, 610 LAGB, and 110 other procedures. At 3-year follow-up, for 1,533 RYGB patients with available data, the percentage of baseline weight lost was 31.5% (IQR, 24.6% to 38.4%). For the 439 LAGB patients with available data at 3 years, the percentage of baseline weight loss was 15.9% (IQR, 7.9% to 23.0%). At 3 years post-surgery, 67.5% and 28.5% of RYGB and LAGB patients, respectively, had at least partial diabetes remission. Dyslipidemia was in remission in 61.9% and 27.1% of RYGB and LAGB patients, respectively. Subsequent bariatric procedures (revision or reversal) were required in 0.3% (95% confidence interval [CI], 0.1% to 0.9%) of the RYGB patients and in 17.5% (95% CI, 13.8% to 21.9%) of LAGB patients.

National Patient-Centered Clinical Research Network — Bariatric Study
The National Patient-Centered Clinical Research Network (PCORnet) Bariatric Study is a large retrospective, comparative study of 65,093 patients aged 20 to 79 years with BMI 35 kg/m2 or greater who underwent RYGB (n = 32,208), LAGB (n = 29,693), or sleeve gastrectomy (SG) (n = 3192) with follow-up through 5 years post-procedure.³² Mean estimated percent total weight loss (%TWL) was calculated at 1, 3, and 5 years in addition to 30-day rates of major adverse events. Study results are summarized in Table 4. This study demonstrates that RYGB is associated with a greater weight loss than SG (p<.001) and that LAGB is associated with the lowest amount of weight loss as observed in a large and diverse patient cohort.

Table 4. National Patient-Centered Clinical Research Network - Bariatric Study Results

	Mean TWL, % (95% CI)			MAE Rate,% (95% CI
Group (na)	1 Year	3 Years	5 Years	30 Days
RYGB (19,029; 9,225; 3,676)	-31.2 (-31.3 to -31.1)	-29.0 (-29.2 to -28.8)	-25.5 (-25.9 to -25.1)	5.0 (NR)
LAGB (1,681; 943; 337)	-13.7 (-14.0 to -13.3)	-12.7 (-13.5 to -12.0)	-11.7 (-13.1 to -10.2)	2.9 (NR)
SG (14,929; 5,304; 1,088)	-25.2 (-25.4 to -25.1)	-21.0 (-21.3 to -20.7)	-18.8 (-19.6 to -18.0)	2.6 (NR)

CI: confidence interval; LAGB: laparoscopic adjustable gastric banding; MAE: major adverse event; NR: not reported; RYGB: Roux-en-Y gastric bypass; SG: sleeve gastrectomy; TWL: total weight loss.
^a Number of patients evaluated at 1, 3, and 5 years, respectively.

Evidence for Specific Types of Bariatric Surgery Procedures
Arterburn et al. (2021) published a retrospective, matched cohort study to investigate weight loss among patients with severe obesity undergoing RYGB, SG, or nonsurgical treatment.³³ Among 17,258 RYGB, 13,900 SG, and 87,965 nonsurgical patients, the 5-year follow-up rate was 72.0%, 70.9%, and 64.5%, respectively. At 1, 5, and 10 years, RYGB patients had a %TWL of -28.35% (95% CI, -28.53 to -28.18), -21.74% (95% CI, -22.02 to -21.45), and -20.18% (95% CI, -21.00 to -19.34), respectively; at the same time points, nonsurgical patients had a %TWL of -0.22% (95% CI, -0.35 to -0.09), -2.24% (95% CI, -2.46 to -2.02), and -4.78% (95% CI, -5.51 to -4.04), respectively. At 1 and 5 years, SG patients had a %TWL of -22.98% (95% CI, -23.19 to -22.76) and -15.99% (95% CI, -16.58 to -15.40), respectively.

Wadden et al. (2019) reported on end-of-trial results from the Look AHEAD: Action for Health in Diabetes (Look AHEAD) trial, which evaluated outcomes in patients with T2D and obesity who had self-selected to receive bariatric surgery after failing an assigned intensive lifestyle intervention (ILI) or a diabetes support and education (DSE) control therapy.³⁴ Patients who received bariatric surgery were significantly more likely to be female (p < .001), younger (p < .001), and have higher BMI at randomization (p < .001). Patients underwent 127 RYGB, 58 LAGB, and 11 SG procedures, respectively. End-of-trial assessments were completed at 4.3 years post-surgery compared to 9.6 years post-randomization for the DSE and ILI participants. Patients undergoing RYGB, LAGB, or SG surgical procedures lost a mean of 22.4% ± 1.0%, 13.0% ± 1.5%, and 16.2% ± 3.3% of baseline weight, respectively. Twelve patients (6.1%) receiving bariatric surgery were randomized with a BMI < 35 kg/m2. The mean BMI was 37.0 ± 5.1, 37.1 ± 5.3, and 42.1 ± 5.8 for DSE, ILI, and surgery groups, respectively (p < .001). Overall, surgically-treated patients lost a mean of 19.3% of baseline weight, compared with 5.8% and 3.3% for the ILI and DSE participants. Full diabetes remission was achieved by 7.6% of bariatric surgery participants compared to 1.1% of ILI and 1.1% of DSE participants. Full remission was significantly more common in surgically treated participants in ILI (RR 6.72; 95% CI, 3.35 to 13.48; p < .001) or DSE (RR 7.07; 95% CI, 3.49 to 14.30; p < .001) groups. Significantly greater reductions in waist circumference (p < .001), triglyceride levels (ILI: p = .03; DSE: p = .02), and hemoglobin A1C (HbA1C) levels (p < .001) were observed in surgically-treated patients compared to ILI or DSE groups. The study was limited by heterogeneity in baseline characteristics and choice of surgical procedure. Results were not stratified by surgery type or BMI range.

Laparoscopic Adjustable Gastric Banding
Systematic Reviews
A 2006 TEC Assessment updated the evidence on LAGB and compared outcomes with gastric bypass.³⁵ This assessment concluded that, for patients considering bariatric surgery, there was sufficient evidence to permit an informed choice between gastric bypass and LAGB. An informed patient might reasonably choose open gastric bypass or LAGB as the preferred procedure. Preoperative counseling should include education on the comparative risks and benefits (e.g., extent of weight loss and frequency and timing of potential complications) of the 2 procedures to optimize choice based on preferences and shared decision making.

Weight loss outcomes from the studies reviewed in the assessment confirmed that weight loss at 1 year was lower for LAGB than for open gastric bypass. The percentage of excess weight loss (EWL) at 1 year was approximately 40%, compared with 60% or higher for open gastric bypass. At time points beyond 1 year, some comparative studies have reported that the difference in weight loss between LAGB and open gastric bypass narrows, but other studies did not. Weight loss outcomes from the 9 single-arm series with the most complete follow-up did not support the hypothesis that the difference in weight loss shrinks after 1 to 2 years of follow-up. It appears more likely from the current data that attrition bias might have accounted for the diminution of the difference in weight loss over time, particularly when patients with bands removed or deflated were excluded from analysis.

These studies also confirmed that short-term (perioperative) complications are very low with LAGB and lower than with open gastric bypass or LAGB. Death was extremely rare, and serious perioperative complications probably occurred at rates less than 1%. The reported rates of long-term adverse events vary considerably. In the comparative trials, reoperations were reported in approximately 25% of patients, while, in the single-arm studies, the composite rate for reoperations were approximately 50% lower (11.9%). The rates of other long-term complications were also highly variable; e.g., the range of rates for band slippage was 1% to 36%, and the range for port access problems was 2% to 20%. These data on long-term complications remain suboptimal. The reporting of long-term complications in these trials was not systematic or consistent. While impossible to determine the precise rates of long-term complications from these data, it is likely that complications have been underreported in many studies due to incomplete follow-up and lack of systematic surveillance. A publication by Ibrahim et al. (2017) reviewed 25,042 Medicare beneficiaries who underwent LAGB surgery; 18.5% (n = 4,636) patients underwent 1 or more reoperation(s). Reoperation was prompted by the need for band removal (41.8%), band and port replacement (28.6%), and other requirements.³⁶ The rates of long-term complications reported in some studies raise concern about the impact of these events on the overall benefit-risk profile for LAGB.

In comparing LAGB with open gastric bypass, there are tradeoffs in terms of risks and benefits. LAGB is a less invasive procedure associated with fewer procedural complications, decreased hospital stay and earlier return to usual activities. However, benefits defined by the amount of weight lost are lower for LAGB. The patterns of long-term complications also differ between the 2 procedures. For LAGB, longer-term adverse events related to the presence of a foreign body in the abdomen will occur and result in reoperations and removal of the band in a minority of patients. Patients who have their bands removed can later be offered an alternative bariatric surgery procedure, such as gastric bypass.

A systematic review by Chakravarty et al. (2012)37, comparing LAGB with other bariatric surgery procedures drew conclusions similar to the TEC Assessment. Reviewers included 5 RCTs. The RCTs found that patients using LAGB lost weight, but less weight than with other procedures (e.g., gastric bypass or SG). However, the short-term complication rate was lower with LAGB, and no difference was found in quality of life after LAGB versus other procedures.

Prospective Studies
Dixon et al. (2018) published a prospective, industry-sponsored study of morbidly obese patients who underwent implantation of the adjustable gastric banding system (LAP-BAND).³⁸ Between 2009 and 2013, 652 patients with a mean BMI of 45.4 kg/m2 were treated at 17 participating centers in the United States and Canada. At 5 years, the explant rate was 8.74% (95% CI, 6.6 to 10.9). Excluding explants, 100 (15.3%) reoperations were necessary during the follow-up period. A mean weight loss of 18.7% was achieved by 2 years and maintained through 5-year follow-up. The study was limited by the lack of control group.

Sleeve Gastrectomy
Systematic Reviews
Sleeve gastrectomy may be performed as a stand-alone procedure or in combination with a malabsorptive procedure, such as the BPD with BPD-DS. It has also been proposed as the first step in a 2-stage procedure, with gastric bypass or BPD as the second stage.

Numerous recent systematic reviews have compared SG and RYGB with regard to effects on weight, comorbidities, and complications (Tables 5 and 6).^{39,40,41,42,43,44}

Lee et al. (2021) performed a meta-analysis evaluating long-term (5 years) outcomes of laparoscopic RYGB versus SG.⁴⁵ A total of 33 studies (N = 2,475) were included. Results demonstrated that RYGB resulted in a significantly greater decrease of BMI compared to SG at 1 and 3 years post-surgery; results at 5 years did not reach statistical significance. A similar trend was seen for the resolution of dyslipidemia. Furthermore, neither RYGB nor SG was superior for the remission of T2D and hypertension at 5 years.

Gu et al. (2020) completed a meta-analysis of the medium- and long-term effects of laparoscopic SG and RYGB.³⁹ The evaluation included 9038 patients from 28 studies. Overall, 5 year follow-up results revealed that laparoscopic RYGB was associated with an improvement in percentage of EWL and remission of T2D, hypertension, and dyslipidemia as compared to laparoscopic SG. Han et al. (2020) also published a systematic review and meta-analysis involving 18 studies (N = 2,917) that compared weight loss and comorbidity resolution between laparoscopic SG and RYGB.⁴⁰ Results from this analysis revealed no significant difference in EWL or T2D resolution between the 2 procedures. Laparoscopic RYGB was found to be superior to SG with regard to dyslipidemia, hypertension, and gastroesophageal reflux disease (GERD) management; however, patients who underwent laparoscopic SG experienced fewer postoperative complications and reoperation rates.

Sharples et al. (2020) performed a systematic review and meta-analysis evaluating long-term (5 years) outcomes of RYGB and SG.⁴¹ Overall, both RYGB and SG resulted in sustained weight loss and comorbidity control with RYGB associated with a greater percent EWL and improved dyslipidemia outcomes.

Shenoy et al. (2020) published a systematic review and meta-analysis of 9 studies that compared laparoscopic SG (LSG) and RYGB in 2240 elderly (> 55 years) patients.⁴² Results revealed no significant differences between the 2 bariatric procedures with regard to the rate of early complications (3.6% LSG vs. 5.8% RYGB; p = .15) and mortality (0.1% vs. 0.8%; p = .27). Additionally, there was no difference in EWL between the procedures at 1 year; however, the authors recommended SG for high-risk elderly patients due to the reduced mortality and complication rates with this procedure. Another systematic review and meta-analysis by Xu et al. (2020) involving 19 studies also concluded that SG was the preferable option for obese patients 60 years and older as it was found to be non inferior to RYGB with regard to efficacy but overall had an improved safety profile.⁴⁶

Osland et al. (2017) published a systematic review and meta-analysis of RCTs comparing laparoscopic vertical SG with RYGB.⁴⁷ The literature search, conducted from 2000 to November 2015, identified 9 RCTs for inclusion (N = 865 patients). Four trials were included in meta-analyses comparing percent EWL between the 2 groups. Results at both 6- and 12-month follow-ups showed that the procedures are comparable. Osland et al. (2020) recently published a continuation of their work that focused exclusively on long-term (5 year) weight outcomes of laparoscopic vertical SG versus RYGB.48, This systematic review and meta-analysis included 5 studies (SG = 520; RYGB = 508) and results revealed that a statistically significant BMI loss was seen with both SG: -11.37 kg/m2 (range, -6.3 to -15.7) and RYGB: -12.6 kg/m2 (range, -9.5 to -15.4) at 5 years. However, differences in reporting parameters limit the ability to reliably compare outcomes using statistical methods and the results may have been impacted by large dropout rates and per protocol analyses of the 2 largest included studies.

A systematic review by Juodeikis and Brimas (2017) summarized evidence on long-term results after SG.⁴⁹ Reviewers included an RCT and 19 retrospective studies, with a total of 2,713 patients who received SG. Mean preoperative BMI was 46.9 kg/m2. Mean duration of follow-up ranged from 5 to 11 years, and mean proportion of patients followed for 5 years was 68.5%. Seventeen studies (N = 1,501 patients) reported 5-year follow-up data. At 5 years, resolution of T2D, arterial hypertension, dyslipidemia, obstructive sleep apnea (OSA), and degenerative joint diseases also improved in most patients. Two studies reported weight loss after 7 and 8 years; percent EWL rates were 56.6% and 54.8%, respectively.

In a meta-analysis of 21 randomized and nonrandomized studies (N = 18,766 patients) comparing SG with laparoscopic RYGB for morbid obesity, Zhang et al. (2015) reported no significant difference in percent EWL from 0.5- to 1.5-year follow-ups.⁵⁰ However, after 1.5 years, RYGB was associated with higher percent EWL (2-year mean difference [MD], 5.77; 95% CI, 4.29 to 7.25; p < .05). Adverse events were more frequent following RYGB (odds ratio [OR] for major complication, 1.29; 95% CI, 1.22 to 3.22; p < .01).

Trastulli et al. (2013) conducted a systematic review of 15 RCTs (N = 1,191 patients) that compared SG with other bariatric procedures.⁵¹ Summary statistics were provided; meta-analyses were not conducted. Reviewers reported mean complication rates with SG of 12.1% (range, 10% to 13.2%) compared with 20.9% with LAGB (range, 10% to 26.4%). Percent EWL ranged from 49% to 81% with SG and from 62.1% to 94.4% with LAGB.

Brethauer et al. (2009) reviewed 36 studies (N = 2,570 patients) in a systematic review of SG as a staged and primary procedure, the largest trials coming from European centers.⁵² Thirteen studies (n = 821 patients) reported on high-risk patients having a staged approach and 24 studies (n = 1,749 patients) on SG as the primary procedure. Mean percent EWL, reported in 24 studies (n = 1,662 patients), was 55.4% overall. Mean postoperative BMI, reported in 26 studies (n = 1,940 patients), decreased from a baseline of 51.2 to 37.1 kg/m2. Other studies reported weight loss in terms of BMI decrease, the percentage of BMI lost, or percentage of total weight lost; all had significant reductions from baseline. Rates of major postoperative complications ranged from 0% to 23.8% for all studies and from 0% to 15.3% in studies with more than 100 patients. Leaks (2.2%), bleeding episodes requiring reoperation (1.2%), and postoperative strictures requiring endoscopic or surgical intervention (0.6%) were reported in the 33 studies (n = 2,570 patients). All extracted studies reported mortality data, with 5 deaths within 30 days of surgery (overall mortality rate, 0.19%; 2 in the high-risk/staged group, 3 in the primary procedure group).

Table 5. Systematic Review Characteristics for Sleeve Gastrectomy

Study	Dates	Studies	Participants	Design	Duration
Lee et al. (2021)45	Through Jan 2019	33	SG = 1,252; RYGB = 1,223	RCTs	1 to 5 y
Gu et al. (2020)39	Through Jan 2019	28	SG = 4,597; RYGB = 4,441	7 RCTs; 6 prospective; 15 retrospective	3 to 7 y
Han et al. (2020)40	Through Jan 2020	18	2,917	9 RCTs; 9 nonrandomized studies of interventions	1 to 82.2 mo
Sharples et al. (2020)41	Through Dec 2018	5	729	RCTs	5 y
Shenoy et al. (2020)42	1991 to 2019	9	SG = 683; RYGB = 1,557	RCTs; observational studies	Minimum follow-up: 1 y
Osland et al. (2017)47	2000 to Nov 2017	9	SG = 437; RYGB = 428	RCTs	3 mo to 5 y
Juodeikis et al. (2017)49	Through May 2016	20	1,626	1 RCT; 19 retrospective	5 to 11 y
Zhang et al. (2015)50	Through Oct 2013	21	18,766	8 RCTs; 13 nonrandomized comparative	1 to 5 y
Trastulli et al. (2013)51	Through Nov 2012	15	1,191	RCTs	6 mo to 3 y
Brethauer et al. (2009)52	1996 to 2009	36	2,570	2 RCTs; 1 cohort; 33 case series	3 mo to 5 y

RCT: randomized controlled trial; RYGB: Roux-en-Y gastric bypass; SG: sleeve gastrectomy.

Table 6. Systematic Review Results for Sleeve Gastrectomy

Study	BMI mean difference (95% CI)	Comorbidities (95% CI)
Lee et al. (2021)45	Mean difference SG vs RYGB: 1 y (16 trials): -1.25 kg/m2 (-2.01 to -0.49) 3 y (5 trials): -1.71 kg/m2 (-2.68 to -0.74) 5 y (4 trials): -1.46 kg/m2 (-3.15 to 0.23)	Remission, SG vs RYGB: T2D (1 y): RR, 0.86 (0.71 to 1.04) T2D (3 y): RR, 0.88 (0.72 to 1.07) T2D (5 y): RR, 0.79 (0.57 to 1.10) Hypertension (5 y): RR, 0.86 (0.68 to 1.10) Dyslipidemia (5 y): RR, 0.68 (0.46 to 1.23)
	Percent EWL (95% CI)	Comorbidities (95% CI)
Gu et al. (2020)39	Weighted mean difference, RYGB and SG: 3 y (13 trials): -4.37 (-8.10 to -0.64) 5 y (9 trials): -2.20 (-3.83 to -0.57)	Remission, RYGB and SG: T2D (3 y): OR, 0.68 (0.48 to 0.95) T2D (5 y): OR, 0.63 (0.41 to 0.96) Hypertension (5 y): OR, 0.51 (0.38 to 0.68) Dyslipidemia (5 y): OR, 0.3 (0.19 to 0.48)
Han et al. (2020)40	Mean difference, RYGB and SG: RCTs: -0.16 (-0.52 to 0.19)	Resolution, RYGB and SG: T2D: RR, 1.07 (0.89 to 1.28) Dyslipidemia: RR, 1.36 (1.17 to 1.59) Hypertension: RR, 1.23 (1.04 to 1.45) symptoms: RR, 0.16 (0.06 to 0.44)
Sharples et al. (2020)41	5 y: RYGB: 65.7% SG: 57.3%	RYGB vs. SG at 5 y: T2D resolution: 37.4% vs. 27.5% Diabetes improvement: 77.5% vs. 74% Hypertension resolution: 60.1% vs. 48.4% Hypertension improvement: 86.4% vs. 76.6% Dyslipidemia resolution: 68.6% vs. 55.2% remission: 60.4% vs. 25%
Shenoy et al. (2020)42	Mean difference, RYGB and SG: -7.79 (-23.96 to 8.38)	Resolution, RYGB and SG: T2D (5 studies): OR, 1.02 (0.63 to 1.66) Hypertension (4 studies): OR, 0.57 (0.35 to 0.93) Obstructive sleep apnea (2 studies): OR, 1.14 (0.55 to 2.34)
Osland et al. (2017)47	Mean difference, SG and RYGB: 6 mo (3 trials): 0.5 (-5.0 to 6.0) 12 mo (2 trials): 7.6 (-0.1 to 15.3)	NR
Juodeikis et al. (2017)49	Mean rates for SG: 5 y (17 trials): 58.4% 7 y (2 trials): 56.6% 11 y (1 trial): 62.5%	Remission/improvement: T2D: 77.8% Hypertension: 68.0% Dyslipidemia: 65.9% Sleep apnea: 75.8%
Zhang et al. (2015)50	Mean difference, RYGB and SG: 6 mo (9 studies): 0.2 (-2.5 to 2.9) 12 mo (15 studies): 2.9 (-0.2 to 6.0) 4 y (3 studies): 2.7 (0.2 to 5.2)	Mean difference resolution, RYGB and SG: T2D (10 studies): 3.3 (2.0 to 5.5) Hypertension (10 studies): 1.3 (0.7 to 2.4) Dyslipidemia (5 studies): 1.1 (0.3 to 1.3) Sleep apnea (7 studies): 1.5 (0.8 to 2.6)
Trastulli et al. (2013)51	Mean by procedure: SG: 49% to 81% LGB: 62% to 94% LAGB: 29% to 48%	T2D: SG, 67% to 100% LGB, 80% to 100%
Brethauer et al. (2009)52	Mean rate overall for SG: 55% (range, 33% to 85%)	Remission/improvement: T2D: > 70% Significant reductions also seen in hypertension, hyperlipidemia, and sleep apnea

BMI: body mass index; CI: confidence interval; EWL: excess body weight loss; LAGB: laparoscopic adjustable gastric banding; LGB: laparoscopic gastric bypass; NR: not reported; OR: odds ratio; RCT: randomized controlled trial; RR: relative risk; RYGB: Roux-en-Y gastric bypass; SG: sleeve gastrectomy; T2D: Type 2 diabetes.

Randomized Controlled Trials
Hofso et al. (2019) published the results of a single-center, triple-blind RCT comparing the efficacy of RYGB (n = 54) versus SG (n = 55) on diabetes remission and ß-cell function in patients with obesity and T2D.⁵³ Inclusion criteria included previously verified BMI ≥ 35 kg/m2 and current BMI ≥ 33.0 kg/m2, HbA1C ≥ 6.5% or use of antidiabetic medications with HbA1C ≥ 6.1%, and age ≥ 18 years. One-year follow-up was completed by 107 (98%) of 109 patients, with 1 patient in each group withdrawing after surgery. In the intention-to-treat population, diabetes remission rates were superior in the gastric bypass group than in the SG group (risk difference 27%; 95% CI, 10 to 44; RR 1.57, 95% CI, 1.14 to 2.16; p = .0054). Results were similar in the per-protocol population (risk difference 27%; 95% CI, 10 to 45; RR 1.57; 95% CI, 1.14 to 2.15; p = .0036). The 2 procedures had a similar beneficial effect on ß-cell function.

Peterli et al. (2018) published a randomized study of adults with morbid obesity treated with either LSG or RYGB.⁵⁴ Two hundred five patients (mean age, 45.5 years; mean BMI, 43.9; 72% women) treated at 4 Swiss bariatric centers were randomly assigned to receive SG (n = 101) or RYGB (n = 104) with 5-year follow-up. Excess BMI loss was 61.6% for SG and 68.3% for RYGB (95% CI, -14.30 to -0.06; p = .22). Gastric reflux remission was seen in 25.0% of SG and 60.4% of RYGB patients. Reoperations or interventions were necessary for 16/101 (15.8%) in the SG group and 23/104 (22.1%) of the RYGB group. The study was limited by the lack of analysis of diabetes remission information, and the results may not be generalizable.

Salminen et al. (2018) published a randomized trial, Laparoscopic Gastric Bypass vs. Laparoscopic Sleeve Gastrectomy in the Treatment of Morbid Obesity (SLEEVEPASS), comparing 5-year outcomes of morbidly obese patients (n = 240; mean age, 48 years; mean baseline BMI, 45.9; 69.6% women) who underwent either LSG (n = 121) or RYGB (n = 119).⁵⁵ Five-year estimated mean percentage excess BMI loss was 49% (95% CI, 45 to 52) for SG and 57% (95% CI, 53 to 61) for gastric bypass. For SG and RYGB, respectively, rates of remission of T2D were 37% (n = 15/41) and 45% (n = 18/40; p > .99). Medication for hypertension was discontinued in 20/68 (29%) SG patients and 37/73 (51%) RYGB patients (p = .02). Overall 5-year morbidity rate was 19% for SG and 26% for RYGB (p = .19), and there was no significant difference in quality of life between groups (p = .85). The study was limited by the following: (1) only a small number (n = 430) of bariatric procedures were performed in Finland at trial initiation in 2008, meaning a learning curve could account for some earlier technical complications, (2) the study had a higher reoperation rate for SG than other trials reported, (3) approximately 20% of patients were lost to follow-up, and (4) there was a lack of reliable information for diabetes duration at baseline.

Wolnerhanssen et al. (2021) pooled 5-year outcomes data from the 2018 studies by Peterli et al. and Salminen et al.⁵⁶ Five-year follow-up was available for 199 of 228 patients after SG and 199 of 229 after RYGB. Patients who underwent SG had an estimated 7% greater excess BMI loss versus RYGB (p < .001). While remission rates for hypertension were better after RYGB versus SG (60.3% vs. 44.9%; p < .049), between-group differences in rates of remission of T2D, OSA, or quality of life scores did not reach statistical significance. The rate of complications was higher after RYGB versus SG (37.2% vs 22.5%; p = .001), but there was no difference in mean Comprehensive Complication Index value (30.6 vs. 31.0 points; p = .859).

An RCT comparing short-term outcomes of laparoscopic SG with gastric bypass was published in 2012.⁵⁷ Trialists compared 30-day outcomes for 117 patients randomized to gastric bypass with 121 patients randomized to LSG. The rate of major complications (no deaths in either group) was 9.4% in the gastric bypass group compared with 5.8% in the LSG group (p = .29). Minor complications were more common in the gastric bypass group than in the LSG group (17.1% vs. 7.4%, p = .02), as were combined major and minor complications (26.5% vs. 13.2%, p = .01).

Karamanakos et al. (2008) carried out a double-blind RCT comparing outcomes of laparoscopic RYGB and LSG on body weight, appetite, fasting, and postprandial ghrelin and peptide YY (levels at 1, 3, 6, and 12 months after surgery).⁵⁸ Thirty-two patients were randomized, half to each procedure. The decrease in body weight and BMI were marked and comparable in each group. EWL was greater after LSG than laparoscopic RYGB at 6 months (55.5% vs. 50.2%; p = .04) and 12 months (69.7% vs. 60.5%; p = .05), all respectively. Fasting peptide YY levels increased after both surgical procedures. Appetite decreased in both groups but decreased more after LSG.

Himpens et al. (2006) reported on a randomized trial comparing LAGB with isolated LSG in 80 patients and reported 3-year follow-up.⁵⁹ Median baseline BMI was 37 kg/m2 (range, 30 to 47) in the LAGB group and 39 kg/m2 (range, 30 to 53) in the SG group. Outcomes of weight loss, feeling of hunger, sweet-eating, complications, and reoperations were recorded at 1- and 3-year follow-ups. Median decrease in BMI in the gastric bypass group was 15.5 kg/m2 (range, 5 to 39) after 1 year and 18 kg/m2 (range, 0 to 39) at 3 years after LAGB. One year after SG, decrease in BMI was 25 kg/m2 (range, 0 to 45) and 27.5 kg/m2 (range, 0 to 48) after 3 years. Median EWL in the LAGB group was 41.4% after 1 year and 48% at 3 years. Median EWL after SG was 58% and 66% at 1 and 3 years, respectively. More patients having SG than LAGB reported a loss of craving for sweets, but the difference was not statistically significant; appeared de novo in more SG than LAGB patients at 1 year, and the relation reversed at 3 years; between-group differences were not statistically significant at either time point. Two SG patients required reoperation for complications. Seven late complications required reoperation after LAGB, including pouch dilations treated by band removal (n = 2) or conversion to RYGB (n = 1), 1 gastric erosion treated by conversion to RYGB, and 3 system disconnections that required reconnection. Four patients had reoperations for lack of efficacy (2 LAGB patients underwent conversion to RYGB, 2 SG patients underwent conversion to DS). The trialists noted that the number of reoperations was significant in both groups and that the severity of complications was greater in the SG group.

Biliopancreatic Diversion With Duodenal Switch
Systematic Review
In an evidence-based review of literature, Farrell et al. (2009) summarized data on BPD with or without DS, RYGB (proximal), and LAGB, and reported that at a mean 1-year follow-up, EWL for BPD with or without DS (outcomes with and without DS not reported separately) was 72% (4 studies; n = 896 patients), 67% for RYGB (7 studies; n = 1,627 patients), and 42% for LAGB (11 studies; n = 4,456 patients).⁶⁰ At mean follow-up of 5 years, EWL for BPD with or without DS was 73% (3 studies; n = 174 patients), 58% for RYGB (3 studies; n = 176 patients), and 55% for LAGB (5 studies; n = 640 patients). Reviewers noted that “given the marked paucity of prospectively collected comparative data among the different bariatric operations, it remains impossible to make definitive recommendations for one procedure over another.”

Nonrandomized Comparative Studies
Skogar et al. (2017) published results from a retrospective mail survey of patients undergoing BPD-DS (n = 113) or RYGB (n = 98) (Tables 7 and 8).⁶¹ Reduction in BMI was statistically larger in patients receiving BPD-DS compared with patients receiving RYGB. Both groups experienced significant reductions in diabetes and OSA. Significant reductions in dyslipidemia were only seen in the group receiving BPD-DS. The overall complication rate was lower for patients undergoing RYGB.

Strain et al. (2007) published a comparative study of 72 patients who underwent RYGB (n = 50) or BPD (n = 22) (Tables 7 and 8).⁶² Choice of surgery was by the surgeon and/or patient, and the patient populations differed by age and time since surgery. Weight loss at 1 year was greater for BPD, with a reduction in BMI of 10.6 kg/m2 (23.3 lb) for BPD compared with 7.5 kg/m2 (16.5 lb) for RYGB (p < .001).

Prachand et al. (2006) published the largest comparative study of 350 super-obese patients with a BMI greater than 22.7 kg (50 lb) who underwent RYGB (n = 152) or Scopinaro BPD combined with the DeMeester BPD-DS (n = 198) (Table 7).⁶³ In this retrospective study, the decision for surgery was made by the surgeon and/or patient. The BPD-DS patients differed from RYGB patients on baseline weight and BMI; mean weight was 167 kg (368 lb; range, 267 to 597 lb) in BPD-DS patients and 157 kg (346 lb; range, 240 to 505 lb) in the RYGB group, and mean BMI was 27 kg/m2 (59 lb; range, 50 to 96 lb) in BPD-DS patients versus 26 kg/m2 (56 lb; range, 50 to 84 lb) in the RYGB group. At 1 year, data were reported for 143 BPD-DS patients and 81 RYGB patients (Table 8). EWL was greater for BPD (64.1%) versus RYGB (55.9%; p < .01), and the reduction in BMI was also greater with BPD (10.7 kg/m2 [23.6 lb]) versus RYGB (8.8 kg/m2 [19.4 lb]; p < .001). Complications and data on the resolution of comorbidities were not reported.

Table 7. Nonrandomized Comparative Study Characteristics for Biliopancreatic Diversion with Duodenal Switch

Study	Country	Dates	Participants	Follow Up
Skogar et al. (2017)61	Sweden	2003 – 2012	BPD-DS: 113 RYGB: 98	4 y
Strain et al. (2007)62	U.S.	2002 – 2005	BPD-DS: 22 RYGB: 50	BPD-DS: 19 mo RYGB: 15 mo
Prachand et al. (2006)63	U.S.	2002 – 2005	BPD-DS: 198 RYGB: 152	3 y

BPD-DS: biliopancreatic diversion with duodenal switch; RYGB: Roux-en-Y gastric bypass.

Table 8. Nonrandomized Comparative Study Results for Biliopancreatic Diversion With Duodenal Switch

Study	Mean Reduction in BMI (SD)		Percent Achieving ≥ 50% EWL
	Presurgery, kg/m2	Postsurgery, kg/m2	pa	1 Year	2 Years	3 Years
Skogar et al. (2017)61 BPD-DS RYGB	56 (6.7) 52 (4.0)	31 (5.5) 36 (7.1)	<.01	NR NR
Strain et al. (2007)62 BPD-DS RYGB	54 (11.9) 48 (6.3)	30 (6.1) 31 (5.0)	<.001	NR NR
		Change in BMI
Prachand et al. (2006)63 BPD-DS RYGB	59 (6.7) 56 (6.8)	27.8 18.9	<.01	83.9 70.4b	89.2 79.3	84.2 59.3b

BMI: body mass index; BPD-DS: biliopancreatic diversion with duodenal switch; EWL: excess weight loss; NR: not reported; RYGB: Roux-en-Y gastric bypass; SD: standard deviation.
^a Between groups, difference in change.
^b p < .05.

Case Series
Strain et al. (2017) reported on the nutrient status of 190 patients receiving BPD-DS after 9 years of follow-up.⁶⁴ At baseline, the patients had a mean age of 43 years and mean BMI of 53 kg/m2. All patients reported taking some supplements. Deficiencies in protein, iron, and calcium developed by year 3 and continued through the study. Zinc deficiencies developed by year 5. Folate levels increased during the study, probably due to the efficacy of the supplement. The authors warned that interventions need to be implemented to improve nutrient status in patients receiving BDP-DS.

The largest case series of this procedure is by Marceau et al. (2009), who reported on their 15-year experience with DS in 1423 patients from 1992 to 2005.⁶⁵ Follow-up evaluations were available for 97% of patients. Survival rate was 92%. After a mean of 7 years (range, 2 to 15), 92% of patients with an initial BMI of 50 kg/m2 or less obtained a BMI of 35 kg/m2 or less, and 83% of patients with a BMI greater than 50 kg/m2 achieved a BMI of less than 40 kg/m2. Diabetes medication was discontinued in 92% and decreased in others. Use of continuous positive airway pressure was discontinued in 92% of patients, and the prevalence of cardiac risk index greater than 5 decreased by 86%. Operative mortality was 1%, the revision rate was 0.7%, and the reversal rate was 0.2%. Revision for failure to lose sufficient weight was needed in only 1.5% of patients. Severe anemia, vitamin deficiency, or bone damage were preventable or easily treated and without documented permanent damage.

Bariatric Surgery for Adults With Class 1 Obesity and Type 2 Diabetes
Clinical Context and Therapy Purpose
The purpose of gastric bypass, SG, BPD, and adjustable gastric banding is to provide treatment options that are alternatives to or improvements on existing therapies, such as standard medical care, in patients who have Class 1 obesity and T2D.

Resolution (cure) or improvement of T2D after bariatric surgery and observations that glycemic control may improve immediately after surgery before a significant amount of weight is lost have promoted interest in a surgical approach to the treatment of T2D. The various surgical procedures have different effects, and gastrointestinal rearrangement seems to confer additional antidiabetic benefits independent of weight loss and caloric restriction. The precise mechanisms are not clear, and multiple mechanisms may be involved. Gastrointestinal peptides (e.g., glucagon-like peptide-1, glucose-dependent insulinotropic peptide, and peptide YY) are secreted in response to contact with unabsorbed nutrients and by vagally mediated parasympathetic neural mechanisms. Glucagon-like peptide-1 is secreted by the L cells of the distal ileum in response to ingested nutrients and acts on pancreatic islets to augment glucose-dependent insulin secretion. It also slows gastric emptying, which delays digestion, blunts postprandial glycemia, and acts on the central nervous system to induce satiety and decrease food intake. Other effects may improve insulin sensitivity. Glucose-dependent insulinotropic peptide acts on pancreatic beta cells to increase insulin secretion through the same mechanisms as glucagon-like peptide-1, although it is less potent. Peptide YY is also secreted by the L cells of the distal intestine and increases satiety and delays gastric emptying.

The following PICO was used to select literature to inform this review.

Populations
The relevant population of interest is individuals who have Class 1 obesity and T2D.

Interventions
The therapy being considered is gastric bypass, SG, BPD, and adjustable gastric banding. Current indications for bariatric surgery view poorly or uncontrolled T2D as a comorbidity whose presence supports the need for surgery in individuals with a BMI of less than 35 kg/m2.

Comparators
Comparators of interest include standard medical care. Treatment for individuals with T2D includes blood glucose regulation and insulin therapy.

Outcomes
The general outcomes of interest are OS, change in disease status, functional outcomes, health status measures, quality of life, treatment-related mortality, and treatment-related morbidity.

The existing literature evaluating gastric bypass, SG, BPD, and adjustable gastric banding as a treatment for T2D has varying lengths of follow-up, ranging from 1 to 5 years.

While studies described below all reported at least 1 outcome of interest, longer follow-up was necessary to fully observe outcomes. One-year follow-up is necessary to demonstrate weight loss efficacy. Longer follow-up to 5 to 10 years is desirable to assess maintenance of weight loss, impact on co-occurring conditions, and appearance of long-term complications.

Study Selection Criteria
Methodologically credible studies were selected using the following principles:

• To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs.
• In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.
• To assess longer term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.
• Consistent with a "best available evidence approach," within each category of study design, studies with larger sample sizes and longer durations were sought.
• Studies with duplicative or overlapping populations were excluded.

This section focuses on RCTs and systematic reviews of RCTs comparing bariatric surgery with medical therapy.

Review of Evidence
Systematic Reviews
Multiple systematic reviews have evaluated bariatric surgery compared to nonsurgical interventions for individuals with T2DM. Summaries of various systematic reviews and meta-analyses on the use of bariatric or metabolic surgery in individuals with a BMI < 35 kg/m2 are available, and report efficacy in achieving weight loss, glycemic control, T2D remission, and mitigation of various cardiovascular disease factors through 1 to 12 years of follow-up.^{66,67,68,69,70,71}

Randomized controlled trials included in systematic reviews are summarized in Table 9.

Table 9. Randomized Controlled Trialsa Included in Systematic Reviews of Bariatric Surgery Procedures Comparing Individuals Who Had Type 2 Diabetes With Controls

Study (Country)	N	BMI Range, kg/m2	Patients With BMI ≤35 kg/m2	Length of FU, years	Definition of Diabetes Remission	Diabetes Remission Rate, n/N (%)			p-Value
						Surgery (LAGB)		Control (DWM)
Simonson et al. (2019)72 (U.S.)	40	30 to 45	39% LAGB; 36% DWM	3	FBS < 126 mg/dL AND HbA1C < 6.5%	13%		5%	.601
						Surgery (LAGB)		Control (ILI/A1C-R)
Dixon et al. (2008)38 (U.S.)	60	30 to 40	22%	2	% achieving FBS < 126mg/dL HbA1C < 6.2% (off meds)	22/30 (93%)		4/30 (13%)	< .001
						Surgery (RYGB)		Control (HILI/A1C-R)
Ikramuddin et al. (2015)73 (U.S.)	120	30 to 40	59%	2	% achieving all 3 ADA goals: HbA1C < 7.0% LDL < 2.59 mmol/L SBP < 130 mmHg	26/60 (43%)		8/59 (14%)	< .001
						Surgery (RYGB)	Control 1 (GCP/A1C-R)	Control 2 (GCP/A1C-S)
Liang et al. (2013)74 (China)	108	> 28g		1	T2D remissionb	28/31 (90%)	0%	0%	< .05
						Surgery (RYGB)	Surgery (LAGB)	Control (HILI/A1C-S)
Courcoulas et al. (2015)75 (U.S.)	61	30 to 40	43%	3	Partial: HbA1C < 6.5% Full: HbA1C < 5.7% (off meds)	8/20 (40%) Full: 3/20 (15%)	6/21 (29%) Full: 1/21 (5%)	0%	.004
Courcoluas et al. (2020)76 (U.S.)				5	Partial: HbA1C < 6.5% Full: HbA1C < 5.7% (off meds)	6/20 (30%) Full: 1/20 (5%)	4/21 (19%) Full: 0	0%	.0208
						Completers
						Surgery (RYGB)	Surgery (LSG)	Control (ILI/A1C-S)
Schauer et al. (2017)77 (U.S.)	150	27 to 43	37%	5h	% HbA1C < 6.0% (meds)	14/49 (29%)	11/49 (23%)	2/38 (5%)	.01c/.03d
						Intention-to-Treat
						26.4%	20.4%	7.3%	.08e/.17f
						Surgery (RYGB)	Surgery (BPD)	Control (GCP/A1C-S)
Mingrone et al. (2015)78 (Italy)	60	35+	0%	5	%HbA1C ≤ 6.5% (% meds ×1 y)	8/19 (42%)	13/19 (68%)	0%	< .001
						Surgery (LAGB)		Control (ILI/A1C-R)
Wentworth et al. (2014)79 (Australia)	51	25 to 30	100%	2	< 125 mg/dL or 200 mg/dL 2-h OGTT (off meds x2 d)	12/23 (52%)		2/25 (8%)	.001
						Surgery (RYGB)		Control (HILI/A1C-S)
Halperin et al. (2014)80 (U.S.)	43	30 to 42	30%	1	% HbA1C < 6.5%	11/19 (58%)		3/19 (16%)	.03

ADA: American Diabetes Association; A1C-R: HbA1C reasonable goal of < 7%; A1C-S: HbA1c stringent goal of <6.5%; BMI: body mass index; BPD: biliopancreatic diversion; DWM: diabetes and weight management; FBS: fasting blood sugar; FU: follow-up; GCP: good clinical practice; HbA1c: hemoglobin A1c; HILI: highly intensive lifestyle intervention; ILI: intensive lifestyle intervention; LAGB; laparoscopic adjustable gastric banding; LDL: low-density lipoprotein; LSG: laparoscopic sleeve gastrectomy; OGTT: Oral Glucose Tolerance Test; RYGB: Roux-en-Y gastric bypass; SBP: systolic blood pressure; T2D: Type 2 diabetes.
^a All RCTs in this table are in the Wu et al. (2016) meta-analysis; 7 of the 8 (except Mingrone et al) are in the Muller-Stich et al. (2015) meta-analysis; the Rao et al. (2015) meta-analysis and the TEC Assessment did not include RCTs. No additional RCTs comparing bariatric surgery with nonsurgical treatment in patients who had T2D were identified.
^b Used as a secondary outcome. Primary outcome was change in left ventricular mass index.
^c Unadjusted (RYGB vs. control).
^d Unadjusted (LSG vs. control).
^e RYGB vs. control.
^f LSG vs. control.
^g WHO Asia-Pacific Obesity Classification.
^h Through February 2017.

Nonrandomized Studies

Table 10. Observational Studies Assessing Bariatric Surgery in Individuals With Type 2 Diabetes With Follow-Up ≥ 3 Year

Study (Country)	N	BMI Range, kg/m2	Patients With BMI ≤35 kg/m2	Length of FU	Interv	Mean HbA1c	Mean BMI, kg/m2	Diabetes Remission Rate
Group 1						Base	FU	Base	FU
Scopinaro et al. (2014) [Scopinaro N, Adami GF, Papadia FS, et al. Effects... 24(7):1036-1043. PMID 24647849] (Italy)	20 treated; 27 matched diabetic controls	30 to 34.9	100%	3 y	RYGB	9.5%	7.0%a	32.9	26.0a	5/20 (25%)
					Control	9.3%	7.7%a	33.0	32.6
Lanzarini et al. (2013) [Lanzarini E, Csendes A, Gutierrez L, et al. Type 2 ... 3;23(2):234-240. PMID 23054574] (Chile)	31	30 to 35	100%	30 moc	RYGB	7.9%	5.5%a	33.1	24.7a	29/31 (94%)
Boza et al. (2011)[Boza C, Munoz R, Salinas J, et al. Safety and effi... 21(9):1330-1336. PMID 21744283] (Chile)	30	< 35	100%	2 y	RYGB	8.1%	≈6.2%a,b	33.5	23.9a	12 mo: 25/30 (83.3%) 2 y: 13/20 (65%)
DePaula et al. (2012) [DePaula AL, Stival AR, DePaula CC, et al. Surgical ... 2;16(5):967-976. PMID 22350720] (Brazil)	202	< 35	100%	39 moc	SG	8.7%	6.1%a	29.7	23.5a	171/198 (86.4%)
Group 2
Lee et al. (2008) [Lee WJ, Wang W, Lee YC, et al. Effect of laparosco ... 8;12(5):945-952. PMID 17940829] (Taiwan)	544 bypass	32 to 77	NR	3 y	Bypass	6.2%	4.8%	41.3	28.0	NR
	116 LAGB		NR		LAGB	5.9%	5.2%	41.9	32.7	NR

Group 1 is defined as poor control optimal medical management (may include insulin). Group 2 is defined as adequate control with medication (may include insulin).
Base: baseline; BMI: body mass index; bypass: mini-gastric bypass; FU: follow-up; HbA1C: hemoglobin A1C; interv: intervention; LAGB; laparoscopic adjustable gastric banding; NR: not reported; RYGB: Roux-en-Y gastric bypass; SG: sleeve gastrectomy.
^a p < .05 (follow-up vs baseline).
^b Estimated from figure.
^c Mean.

Wu et al. (2016) published a meta-analysis of studies comparing bariatric surgery with nonsurgical interventions for patients who had T2D.⁶⁷ Eight RCTs with 619 patients were included. RCTs addressed RYGB (6 studies), LAGB (3 studies), LSG (1 study), and BPD (1 study). Mean BMI across studies was 29 kg/m2 or higher; in 6 of 8 studies, mean BMI was 35 kg/m2 or higher. One study had a 5-year follow-up, and the others had 1 to 3 years of follow-up. The study with a 5-year follow-up, by Mingrone et al. (2015), was limited to patients with a BMI of at least 35 kg/m2.[Mingrone G, Panunzi S, De Gaetano A, et al. Bariat.... 6(9997): 964-73. PMID 26369473] All 8 studies reported remission of T2D as an efficacy endpoint. A pooled analysis found a significantly higher rate of T2D remission in the bariatric surgery versus the nonsurgical treatment group (RR, 5.76; 95% CI, 3.15 to 10.55; p < .001). Another diabetes-related outcome (mean reduction in HbA1C levels) was significantly greater after bariatric surgery than nonsurgical treatment (MD, -1.29; 95% CI, -1.70 to -0.87). Also, there was a significantly greater reduction in BMI with bariatric surgery than with nonsurgical treatment (MD, -5.80; 95% CI, -6.95 to -4.64; p < .001). Since the publication of the Wu et al. (2016) meta-analysis, 5-year follow-up has been reported for the Schauer et al. (2017) RCT, which is shown in Table 18. When the Wu et al. (2016) meta-analysis was published, only 3-year findings of the Schauer et al. (2017) study were available. The study included patients with T2D who had a BMI of 27 to 43 kg/m2. The RCTs evaluating bariatric surgery in patients with T2D, including the 5-year follow-up of the Schauer et al. (2017) study, are summarized in Table 18.

Yan et al. (2016) published a systematic review of RCTs comparing gastric bypass with medical treatment in obese patients (i.e., BMI ≥ 30 kg/m2) who had T2D. [Yan Y, Sha Y, Yao G, et al. Roux-en-Y Gastric Bypa.... ; 95(17): e3462. PMID 27124041] The primary study outcome was remission of T2D, which was reported in 5 of the 6 studies. A pooled analysis found a significantly higher remission rate after gastric bypass than after medical treatment (OR, 76.37; 95% CI, 20.70 to 271.73; p < .001). Also, a pooled analysis found a significantly lower final BMI in the gastric bypass group than in the medical treatment group (MD, -6.54 kg/m2; 95% CI, -9.28 to -3.80 kg/m2; p < .001).

Muller-Stich et al. (2015) published a systematic review of RCTs and observational studies on bariatric surgery in patients with T2D and a BMI less than 35 kg/m2. [Muller-Stich BP, Senft JD, Warschkow R, et al. Sur.... ;261(3):421-429. PMID 25405560] Eleven comparative trials of medical therapy versus bariatric surgery were included, with 5 RCTs and 6 nonrandomized comparative studies identified. Follow-up was between 1 and 3 years. The primary outcome reported was remission of diabetes. On combined analysis, bariatric surgery was associated with a higher remission rate than medical therapy (OR, 14.1; 95% CI, 6.7 to 29.9; p < .001). On secondary outcomes, surgery was associated with a greater decrease in BMI (MD, -5.5 kg/m2; 95% CI, -6.7 to -4.3; p < .001), a lower HbA1c level (MD, -1.4%; 95% CI, -1.9 to -0.9; p < .001), lower rates of hypertension (OR, 0.25; 95% CI, 0.12 to 0.50; p < .001), and lower rates of dyslipidemia (OR, 0.21; 95% CI, 0.10 to 0.44; p < .001).

Also, Rao et al. (2015) published a meta-analysis of short-term outcomes for patients with T2D and a BMI of 35 kg/m2 or less who underwent RYGB. [Rao WS, Shan CX, Zhang W, et al. A meta-analysis o.... 5;39(1):223-230. PMID 25159119] Nine articles were included (N = 343 patients). After 12 months, patients with T2D had a significant decrease in BMI (weighted MD, -7.42; 95% CI, -8.87 to -5.97; p < .001) and improvements in HbA1c levels (weighted MD, -2.76; 95% CI, -3.41 to -2.11; p < .000). Reviewers reported that longer term follow-up would be needed.

Previously, a 2012 TEC Assessment evaluated bariatric surgery in diabetic patients with a BMI less than 35 kg/m2. [Technology Eval.... ssments. 2012;Volume 27:Tab 2.] The evidence consisted mainly of case series. The Assessment identified only observational studies. Based on the data, the assessment concluded that gastric bypass met TEC criteria as a treatment for diabetes in patients with a BMI less than 35 kg/m2 but that other procedures did not meet the TEC criteria for this indication:

• There were no randomized trials comparing bariatric surgery with medical treatment for diabetic subjects with a BMI less than 35 kg/m2. There was only 1 randomized trial comparing 2 bariatric procedures. Therefore, studies were categorized by procedure type and presented as case series, regardless of the underlying study type.
• Nine studies reported diabetes remission rates and other outcomes in subjects undergoing gastric bypass. Diabetes remission rates varied between 48% and 100% at follow-up times of 1 year and beyond. One study was a randomized trial of gastric bypass versus SG; in it, diabetes remission associated with gastric bypass was 93% versus 47% for SG at 1 year.
• Two studies reported outcomes of SG. Diabetes remission rates were 55% and 47% at 1 year.
• One study reported outcomes of ileal interposition. The diabetes remission rate at a mean follow-up time of 39.1 months was 78.3%.
• Two studies reported outcomes of gastric banding. The outcomes reported were not considered to be rigorous, because the only measure of diabetes outcome was the withdrawal of diabetes medication. Reported remission rates were 27.5% and 50% at variable follow-up times.
• One study of BPD reported a remission rate of 67% for subjects with a BMI between 30 and 35 kg/m2 and 27% for subjects with a BMI between 25 and 30 kg/m2 at 12-month follow-up.
• One study reported outcomes of duodenojejunal exclusion. Subjects in this study had more severe diabetes than subjects enrolled in other studies; 100% were on insulin treatment, and the duration of diabetes was between 5 and 15 years. The diabetes remission rate was 17% at 6 months.

Section Summary: Bariatric Surgery in Adults With Class 1 Obesity and Type 2 Diabetes
Systematic reviews of RCTs and observational studies have found that certain types of bariatric surgery are more efficacious than medical therapy as a treatment for T2D in adults with obesity, including those with a BMI between 30 and 34.9 kg/m2. The greatest amount of evidence assesses gastric bypass, with some comparative studies on LAGB, LSG, and BPD. Systematic reviews have found significantly greater remission rates of diabetes, decrease in HbA1c levels, and decrease in BMI with bariatric surgery than with nonsurgical treatment. The efficacy of surgery is balanced against the short-term risks of the surgical procedure. Most RCTs in this population have 1 to 5 years of follow-up data.

Bariatric Surgery in Adults With a Body Mass Index Less Than 35 kg/m2 Who Do Not Have Type 2 Diabetes
Clinical Context and Therapy Purpose
The purpose of any bariatric surgery procedure is to provide a treatment option that is an alternative to or improvement on existing therapies, such as standard medical care, in patients who are not diabetic and a BMI less than 35 kg/m2.

The following PICO was used to select literature to inform this review.

Populations
The relevant population of interest is individuals with a BMI less than 35 kg/m2 who do not have Type 2 diabetes.

Interventions
The therapy being considered is any bariatric surgery procedure.

Comparators
Comparators of interest include standard medical care for nondiabetic patients.

Outcomes
The general outcomes of interest are OS, change in disease status, functional outcomes, health status measures, quality of life, treatment-related mortality, and treatment-related morbidity.

The existing literature evaluating any bariatric surgery procedure has varying lengths of follow-up, ranging from 1 to 3 years. While studies described below all reported at least 1 outcome of interest, longer follow-up was necessary to fully observe outcomes. One-year follow-up is necessary to demonstrate weight loss efficacy. Longer follow-up to 5 to 10 years is desirable to assess maintenance of weight loss, impact on co-occurring conditions, and appearance of long-term complications.

Study Selection Criteria
Methodologically credible studies were selected using the following principles:

• To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs.
• In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.
• To assess longer term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.
• Consistent with a "best available evidence approach," within each category of study design, studies with larger sample sizes and longer durations were sought.
• Studies with duplicative or overlapping populations were excluded.

Review of Evidence
Systematic Reviews
A 2012 TEC Assessment evaluated LAGB in individuals without diabetes who had a BMI less than 35 kg/m2.⁸¹ This Assessment was prompted by FDA approval of LAP-BAND for this indication in 2011. The TEC Assessment concluded that LAGB did not meet TEC criteria in these patients and made the following summary statements:

• The evidence on LAGB for patients with lower BMIs is limited both in quantity and quality. There was only 1 small RCT, which had methodologic limitations, a nonrandomized comparative study based on registry data, and several case series. Using the GRADE evaluation, the quality of evidence on the comorbidity outcomes was judged to be low, and the quality of the evidence on the weight loss outcomes was judged to be moderate.
• The evidence was sufficient to determine that weight loss following LAGB was greater than with nonsurgical therapy.
• Direct data on improvement in weight-related comorbidities was lacking. The limited evidence was not sufficient to conclude that the amount of weight loss is large enough that improvements in weight-related comorbidities could be assumed.
• There were very few data on quality of life in this population of patients.
• The frequency and impact of long-term complications following LAGB were uncertain, and this uncertainty has been 1 of the main reasons why it is difficult to determine whether the benefit of LAGB outweighs the risk for this population. While the short-term safety of LAGB has been well-established, the long-term adverse events occur at a higher rate and are less well-defined.

Section Summary: Bariatric Surgery in Adults With a Body Mass Index Less Than 35 kg/m2 Who Do Not Have Type 2 Diabetes
There is limited evidence for bariatric surgery in patients who are not diabetic and have a BMI less than 35 kg/m2. A few small RCTs and case series have reported a loss of weight and improvements in comorbidities for this population. However, the evidence does not permit conclusions on the long-term risk-benefit ratio of bariatric surgery in this population.

Bariatric Procedures Other Than Open or Laparoscopic Gastric Bypass Using a Roux-en-Y, Laparoscopic Adjustable Gastric Banding, Open or Laparoscopic Sleeve Gastrectomy, or Open or Laparoscopic Biliopancreatic Bypass/Diversion With Duodenal Switch
This section briefly summarizes the key evidence on additional bariatric procedures that are used infrequently.

Biliopancreatic Diversion Without Duodenal Switch
A TEC Assessment reviewed the available observational studies and concluded that weight loss was similar after BPD without the DS and gastric bypass.35, However, BPD without DS leads to complications, especially long-term nutritional and vitamin deficiencies.^82,83

Vertical-Banded Gastroplasty
A TEC Assessment identified 8 nonrandomized comparative studies evaluating VBG with gastric bypass.⁸⁴ The assessment found that weight loss was significantly greater with open gastric bypass than with VBG. Also, VBG has relatively high rates of complications, revisions, and reoperations.

Two-Stage Bariatric Surgery Procedures
The evidence from an RCT⁸⁵ and several case series86,87,88, does not support a 2-stage bariatric surgery procedure for improving outcomes in patients with extreme levels of obesity. There is no evidence to suggest that weight loss is improved or that complications are reduced by this approach. Most patients who receive SG as the initial procedure lose sufficient weight during the first year so that a second procedure is no longer indicated. Also, patients undergoing a 2-stage procedure are at risk for complications from both procedures; therefore, it is likely that overall complications are increased by this approach.

Laparoscopic Gastric Plication
There is a shortage of comparative studies, especially RCTs, comparing the safety and efficacy of laparoscopic gastric plication with other bariatric surgery procedures. A 2021 systematic review demonstrated that SG is superior to greater curvature gastric plication with regard to providing effective weight loss through 24 months; statistical significance was not reached at 36 months.⁸⁹ The difference in the improvement of comorbidities and risk of major complications or mortality did not reach statistical significance between groups. One RCT compared endoscopic gastric plication with a sham procedure, reporting 1-year follow-up results in favor of the intervention.⁹⁰ Longer-term follow-up and additional comparative studies are needed.

Single Anastomosis Duodeno-ileal Bypass With Sleeve Gastrectomy
A systematic review of 12 observational studies concluded that SADI-S was associated with promising weight loss and comorbidity resolution.⁹¹ No published controlled trials have evaluated SADI-S. A comparative chart review found that patients without diabetes experienced significantly better weight loss and lipid profiles with SADI-S than with RYGB and patients who had diabetes experienced significantly higher rates of remission with SADI-S than with RYGB.⁹² Long-term safety and efficacy outcomes and comparative RCTs are still needed.

Duodenojejunal Sleeve
A systematic review of evidence on a duodenojejunal sleeve included 5 RCTs and found significantly greater short-term weight loss (12 to 24 weeks) with duodenojejunal sleeves compared with medical therapy.⁹³ There was no significant difference in symptom reduction associated with diabetes. However, all RCTs had small sample sizes and were judged by the systematic reviewers to be at high-risk of bias.

Intragastric Balloon Devices
Evidence includes RCTs,^94,95 a case series with long-term follow-up on 1 of the devices,⁹⁶ and systematic reviews on various intragastric balloon (IGB) devices.^97,98,99,100 RCTs have found significantly better weight loss outcomes with IGB devices compared with sham treatment or LT alone. One RCT followed patients for an additional 6 months after IGB removal and found sustained weight loss. A large case series with follow-up up to 5 years has suggested that patients regain weight over time. Additional long-term follow-up data are needed. There are some adverse events, and in a minority of cases, these adverse events can be severe. The FDA wrote 2 letters in 2017 to health care providers, 1 warning of spontaneous balloon inflation and pancreatitis and the other reporting 5 unanticipated deaths occurring in 2016 to 2017 following the IGB procedure. In June 2018, the FDA reported that, since 2016, a total of 12 deaths occurred in patients with liquid-filled intragastric balloons worldwide; 7 of these deaths were in patients in the U.S. Health care providers are encouraged to monitor patients receiving IGBs.

Aspiration Therapy Device
The evidence consists of an RCT with 4 years of follow-up101, and a small case series with up to 2 years of follow-up.¹⁰² The RCT found significantly greater weight loss (measured several ways) with AT compared with LT at 1 year. Forty of 58 patients (69%) achieved at least 10% TWL at 4 years or at time of study withdrawal; however, only 15/111 initial AT patients completed the study through 4 years. In addition to a high degree of missing data, the PATHWAY study noted a potentially high degree of adverse events related to A-tube malfunction, an element of the therapy which is expected to require replacement within approximately 3.5 years postgastrostomy in 50% of cases. The impact of this on health outcomes compared to existing surgical approaches is unknown. The case series followed only 15 patients more than 1 year; at 2 years, study completers had not regained weight and instead had lost additional excess weight. The total amount of data on AT remains limited and additional studies need to be conducted before conclusions can be drawn about the long-term effects of treatment on weight loss, metabolism, safety, and nutrition.

Bariatric surgeries performed in 2 stages have been proposed as a treatment option, particularly for patients with “super-obesity” defined as a BMI greater than 50 kg/m2. The rationale for a 2-stage procedure is that the risk of an extensive surgery is prohibitive in patients who are extremely obese. Therefore, a procedure with low-risk (usually an SG) is performed first. After the patient loses some weight, thus lowering the surgical risk, a second more extensive procedure (e.g., BPD) is performed.

Revision Bariatric Surgery
Clinical Context and Therapy Purpose
The purpose of revision bariatric surgery is to address complications of a procedure or a procedure that has failed. Severe GERD is one of the most common indications for revision surgery.

The following PICO was used to select literature to inform this review.

Populations
The relevant population of interest is individuals who have had bariatric surgery.

Interventions
The therapy being considered is revision bariatric surgery to address perioperative or late complications of a bariatric procedure, to address bariatric surgery that has failed due to dilation of the gastric pouch or dilation proximal to an adjustable gastric band, or to address severe GERD refractory to medical treatment.

Comparators
Comparators of interest include standard medical care without revision surgery.

Outcomes
The general outcomes of interest are OS, change in disease status, functional outcomes, health status measures, quality of life, treatment-related mortality, and treatment-related morbidity.

The existing literature evaluating revision bariatric surgery has varying lengths of follow-up, ranging from 1 to 3 years. While studies described below all reported at least 1 outcome of interest, longer follow-up was necessary to fully observe outcomes. One-year follow-up is necessary to demonstrate weight loss efficacy. Longer follow-up of 5 to 10 years is desirable to assess maintenance of weight loss, impact on co-occurring conditions, and appearance of long-term complications.

Study Selection Criteria
Methodologically credible studies were selected using the following principles:

• To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs.
• In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.
• To assess longer term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.
• Consistent with a "best available evidence approach," within each category of study design, studies with larger sample sizes and longer durations were sought.
• Studies with duplicative or overlapping populations were excluded.

Review of Evidence
Systematic Reviews
Matar et al. (2021) published a systematic review of 556 patients (n = 17 studies) who underwent RYGB for SG-related complications, including GERD (30.4% cases) and insufficient weight loss and weight regain (52% of cases).103, The mean BMI at the time of conversion ranged from 33.3 to 48.3 kg/m2. The pooled baseline BMI at conversion was 38.5 kg/m2 (95% CI, 36.49 to 40.6), at 6 months was down to 28.6 kg/m2 (95% CI, 16.1 to 41.0), and after 1 year was up to 32.1 kg/m2 (95% CI, 25.50 to 38.7). The pooled mean %TWL after completion of treatment was 25.2% (95% CI, 12.8 to 37.5) at 6 months and 22.8% (95% CI, 13.5 to 32.1) at 1 year. There was a 16.4% complication rate at 30 days, which decreased to 11.4% after 30 days. At 1-year post RYGB, the rate of resolution for common comorbidities was as follows: GERD, 79.7% (95% CI, 59.6 to 91.3); T2D, 57.7% (95% CI, 36.9 to 76.1); and hypertension, 49.4% (95% CI, 25.8 to 73.3).

Parmar et al. (2020) published a systematic review of 1075 patients (n = 17 studies) who underwent 1 anastomosis/mini gastric bypass (OABG-MGB) as a revisional bariatric procedure after failure of a primary LAGB and SG.¹⁰⁴ No RCTs were available on this topic and no meta-analyses were performed as part of this systematic review. The most commonly reported reason for revisional surgery was poor response (81%) followed by gastric band failure (35.9%), GERD (13.9%), intolerance (12.8%), staple line disruption (16.5%), pouch dilatation (17.9%), and stomal stenosis (10.3%). Results revealed that after the revisional OABG-MGB, the mean percent EWL was 50.8% at 6 months, 65.2% at 1 year, 68.5% at 2 years, and 71.6% at 5 years. Resolution of comorbidities after OAGB-MGB was significant with 80.5% of patients with T2D, 63.7% of patients with hypertension, and 79.4% of patients with reporting resolution. The overall readmission rate following OAGB-MGB was 4.73%, the mortality rate was 0.3%, and the leak rate was 1.54%. Although the authors concluded that OAGB-MGB is a safe and effective choice for revisional bariatric surgery, RCTs on this topic are needed as currently only retrospective cohort studies with heterogenous data are available.

Brethauer et al. (2014) conducted a systematic review of reoperations after primary bariatric surgery for the American Society for Metabolic and Bariatric Surgery that included 175 studies, most of which were single-center retrospective reviews.¹⁰⁵ The review is primarily descriptive, but made the following conclusions: “The current evidence regarding reoperative bariatric surgery includes a diverse group of patient populations and procedures. The majority of the studies are single institution case series reporting short- and medium-term outcomes after reoperative procedures. The reported outcomes after reoperative bariatric surgery are generally favorable and demonstrate that additional weight loss and co-morbidity reduction is achieved with additional therapy. The risks of reoperative bariatric surgery are higher than with primary bariatric surgery and the evidence highlights the need for careful patient selection and surgeon expertise.”

Nonrandomized Studies
A retrospective study reported by Dang et al. (2023) analyzed serious complications and mortality in patients who underwent revision surgery (conversion of SG to RYGB, N = 13,432) or primary RYGB (N = 84,543) in 2020 and 2021.¹⁰⁶ GERD was the most common indication for revision (55.3%), followed by weight regain (24.4%), and inadequate weight loss (12.7%). Revisional RYGB after SG was associated with a higher rate of serious complications than primary RYGB (7.2% vs. 5.0%, p < .001). There was no significant difference in 30-day mortality.

Petrucciani et al. (2021) published a retrospective analysis of 215 patients who underwent revisional OAGB with a biliopancreatic limb of 150 cm after failing LAGB at a single center between 2010 and 2016.¹⁰⁷ The indication for surgery was weight loss failure in 30.7% of cases and long-term complications in the remaining cases. The mean BMI at the time of OAGB was 42 kg/m2. At 2 years after OAGB, 9.7% of patients were lost to follow-up, BMI was down to 28 ± 5.5 kg/m2, %EWL was 88.2 ± 23.9, and %TWL was 38.7 ± 9.3. At 5 years after OAGB, 16.6% of patients were lost to follow-up, BMI was slightly up to 29.2 ± 5.8 kg/m2, %EWL was 82.4 ± 25, and %TWL was 36.1 ± 10. Overall postoperative morbidity was 13.5% with a 5.9% rate of postoperative abscess with or without staple line leak. Treatment-resistant occurred in 21.3% of patients; conversion to RYGB was required in 4.2% of cases.

Almalki et al. (2018) published a retrospective analysis of patients diagnosed with failed restrictive procedure who underwent revision bariatric surgery.¹⁰⁸ One hundred sixteen patients between 2001 and 2015 had revision RY gastric bypass (R-RYGB; n = 35) or revision single anastomosis- (mini-) gastric bypass (R-SAGB; n = 81); the primary indications for revisional procedures were weight regain (50.9%), inadequate weight loss (31%), and intolerance (18.1%). Major complications occurred in 12 (10%) patients without significant difference between groups (R-SAGB, n = 9; R-RYGB, n = 3). At 1 year after revision surgery, the R-SAGB group (76.8% EWL) showed better weight loss than R-RYGB (32.9% EWL; p = .001). In the 37.1% of patients available for follow-up at 5 years, R-SAGB had significantly lower hemoglobin levels than R-RYGB (8.2 ± 3.2 g/dl vs. 12.8 ± 0.5 g/dl; p = .03). The study was limited by its retrospective nature, relatively short follow-up time, and lack of consideration of data related to patient compliance.

Sudan et al. (2015) reported on safety and efficacy outcomes for reoperative bariatric surgeries using data from a national registry, the Bariatric Outcomes Longitudinal Database.¹⁰⁹ The Bariatric Outcomes Longitudinal Database was a large, multi-institutional bariatric surgery‒specific database to which data were submitted from 2007 through 2012 by 1029 surgeons and 709 hospitals participating in the Bariatric Surgery Centers of Excellence program. Surgeries were classified as primary or reoperative bariatric. Reoperations were further divided into corrective surgeries (when complications or incomplete treatment effect of a previous bariatric operation was addressed, but the initial operation was not changed) or conversions (when an index bariatric operation was changed to a different type of bariatric operation or a reversal restored original anatomy). Of 449,473 bariatric operations in the database, 420,753 (93.6%) operations had no further reoperations (primary operations) while 28,270 (6.3%) underwent reoperations. Of the reoperations, 19,970 (69.5%) were corrective and 8750 (30.5%) were conversions. The primary bariatric operations were RYGB (n = 204,705 [49.1%]), LAGB (n = 153,142 [36.5%]), SG (n = 42,178 [10%]), and BPD-DS (n = 4260 [1%]), with the rest classified as miscellaneous. LAGB was the most common primary surgery among conversions (57.5% of conversions; most often [63.5%] to RYGB). Compared with primary operations, mean hospital length of stay was longer for corrections (2.04 days vs. 1.8 days, p < .001) and for conversions (2.86 days vs. 1.8 days, p < .001). Mean percent EWL at 1 year was 43.5% after primary operation, 39.3% after conversions, and 35.9% after corrective operations (statistical comparison not reported). One-year mortality was higher for conversions (0.31%) than for primary surgeries (0.17%; p < .001), with no statistically significant difference for corrections (0.24%) compared with primary surgeries (0.17%; p = not significant [NS]). One-year serious adverse event rates were higher for conversions (3.61%) than for primary operations (1.87%; p < .001), with no statistically significant difference for corrections (1.9%) compared with primary operations (1.87%; p = NS). The authors concluded that reoperation after primary bariatric surgery is relatively uncommon, but generally safe and efficacious when it occurs.

Endoscopic Revision Procedures
While bariatric surgery revision or correction can be conducted using standard surgical approaches, novel endoscopic procedures are being developed. Some procedures use devices also being evaluated for the endoscopic treatment of (see evidence review 2.01.38). The published data on the use of these devices for treatment of regained weight is limited. Published case series have reported results using a number of devices and procedures (including sclerosing injections) as a treatment for this condition. The largest series (2007) found involved 28 patients treated with a sclerosing agent (sodium morrhuate).110, Reported trials that used 1 of the suturing devices had fewer than 10 patients. For example, Herron et al. (2008) reported on a feasibility study in animals.¹¹¹ Thompson et al. (2006) reported on a pilot study with changes in anastomotic diameter and weight loss in 8 patients who regained weight and had dilated gastrojejunal anastomoses after RYGB.¹¹² No comparative trials were identified; comparative trials are important because of the known association between an intervention and short-term weight loss.

The StomaphyX device, which has been used in this approach, was cleared by FDA through the 510(k) process. It was determined to be equivalent to the EndoCinch system, which has 510(k) marketing clearance for endoscopic suturing for gastrointestinal tract surgery. Eid et al. (2014) reported on results from a single-center RCT that compared the StomaphyX device with a sham procedure for revisions in patients with prior weight loss after RYGB at least 2 years earlier.¹¹³ Enrollment was initially planned for 120 patients, but the trial was stopped prematurely after 1-year follow-up was completed by 45 patients in the StomaphyX group and 29 patients in the sham control group because preliminary analysis failed to achieve the primary efficacy endpoint in at least 50% of StomaphyX patients. The primary 12-month efficacy endpoint (reduction in pre-RYGB excess weight by ≥ 15%, excess BMI loss, and BMI < 35 kg/m2) was achieved by 10 (22.2%) of 45 in the StomaphyX group and 1 (3.4%) of 29 in the sham control group (p < .01).

A 2009 survey of American Society for Metabolic and Bariatric Surgery members (bariatric surgeons) indicated different risk tolerance and weight loss expectations for primary and revisional endoscopic procedures.⁵² The surgeons were “willing to accept less weight loss and more risk for revisional endoluminal procedures than for primary endoluminal procedures.” The durability of the procedures was a concern, and most surgeons were unwilling to consider the procedures until their efficacy has been proven. A 2013 systematic review of studies reporting outcomes after endoluminal revision of primary bariatric surgery conducted by the American Society for Metabolic and Bariatric Surgery concluded: “The literature review shows the procedures on the whole to be well tolerated with limited efficacy. The majority of the literature is limited to small case series. Most of the reviewed devices are no longer commercially available."¹¹⁴

Cohen et al. (2019) conducted a systematic review evaluating the safety and efficacy of endoscopic gastroplasty for medically uncontrolled obesity.¹¹⁵ Nine observational studies and a single RCT were identified by the authors. Follow-up duration in the majority of studies was limited to 6 to 12 months with several studies reporting high rates of loss to follow-up. Percent total body weight loss ranged from -15.1% to 19.5%. Reduction in BMI ranged from -1.69 to -7.5 kg/m2. Serious adverse events ranged from 2% to 10%. The quality of the current evidence was graded very low to moderate, with limited long-term data on weight loss durability and procedure safety.

Section Summary: Revision Bariatric Surgery
Systematic reviews and case series have shown that patients receiving revision bariatric surgery experienced satisfactory weight loss and reduced comorbidities including GERD. Data from a multinational bariatric surgery database has found that corrective procedures following primary bariatric surgery are relatively uncommon but generally safe and efficacious. A large retrospective analysis found a serious complication rate of 7.2% for conversion to RYGB in 13,432 individuals and no difference in 30-day mortality compared to primary RYGB.

Bariatric Surgery in Adolescents
Clinical Context and Therapy Purpose
The purpose of bariatric surgery is to provide a treatment option that is an alternative to or an improvement on existing therapies, such as standard medical care, in individuals who are adolescents with obesity.

The following PICO was used to select literature to inform this review.

Populations
The relevant population of interest is individuals who are adolescents with obesity. While guidelines for bariatric surgery in adolescents are not uniform, most use weight-based criteria that parallel those for adults.

Interventions
The therapy being considered is open or laparoscopic gastric bypass, laparoscopic adjustable gastric banding, or open or laparoscopic sleeve gastrectomy.

Comparators
Comparators of interest include standard medical care. Treatment for adolescent children with obesity includes physical exercise, low carbohydrate dieting, and low-fat dieting.

Outcomes
The general outcomes of interest are OS, change in disease status, functional outcomes, health status measures, quality of life, treatment-related mortality, and treatment-related morbidity.

The existing literature evaluating gastric bypass, LAGB, or SG as a treatment for obesity has varying lengths of follow-up, ranging from 1 to 6 years. While studies described below all reported at least 1 outcome of interest, longer follow-up was necessary to fully observe outcomes. One-year follow-up is necessary to demonstrate weight loss efficacy. Longer follow-up to 5 to 10 years is desirable to assess maintenance of weight loss, impact on co-occurring conditions, and appearance of long-term complications.

Study Selection Criteria
Methodologically credible studies were selected using the following principles:

• To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs.
• In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.
• To assess longer term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.
• Consistent with a "best available evidence approach," within each category of study design, studies with larger sample sizes and longer durations were sought.
• Studies with duplicative or overlapping populations were excluded.

Bariatric Surgery Techniques in Adolescents
Review of Evidence
Systematic Reviews
Qi et al. (2017) published a systematic review and meta-analysis on the use of bariatric surgery for the treatment of adolescents with obesity (Table 11).¹¹⁶ In a literature search conducted through July 2017, 49 studies were identified for inclusion. Study quality was assessed using the Newcastle-Ottawa Scale. Age of patients ranged from 14 to 20 years. BMI ranged from 34 to 63 kg/m2. Overall results showed significant improvements in BMI as well as glycemic and lipid control with various bariatric surgery techniques. RYGP showed the largest improvements compared with other procedures, with LAGB and SG also showing improvements in this population.

In a systematic review of 23 studies, Black et al. (2013) concluded that the available literature demonstrated a high rate of significant short-term weight loss after bariatric surgery (Table 11).¹¹⁷ The literature search was conducted through January 2013. Quality assessment of the included studies was not discussed. Ages of patients at the time of surgery ranged from 5 to 23 years. A meta-analysis showed significant reductions in BMI. Meta-analyses were not conducted on the resolution of comorbidities due to heterogeneity in reporting. However, most cases of hypertension, OSA, T2D, and dyslipidemia were reported to have resolved at 1-year follow-up. Reviewers noted that complication and comorbidity rates were not well-defined.

Treadwell et al. (2008) conducted a systematic review and meta-analysis of the published evidence on bariatric surgery in adolescents (Table 11).¹¹⁸ Their analysis included English-language articles on currently performed procedures when data were separated by procedure, and there was a minimum 1-year follow-up for weight and BMI. Studies must have reported outcomes data for 3 or more patients ages 21 years or younger, representing at least 50% of pediatric patients enrolled at that center. Nineteen studies reported on between 11 and 68 patients who were 21 years or younger. Eight studies of LAGB (mean BMI, 45.8 kg/m2; median age range, 15.6 to 20 years); 6 studies on RYGB (mean BMI, 51.8 kg/m2; median age range, 16 to 17.6 years); 5 studies of other procedures (mean BMI, 48.8 kg/m2; median age range, 15.7 to 21 years) were included.

Meta-analyses of BMI at longest follow-up indicated sustained and clinically significant reductions for both LAGB and RYGB (Table 12). Comorbidity resolution was sparsely reported, but surgery appeared to resolve some medical conditions, including diabetes and hypertension; 2 studies of LAGB showed large rates of diabetes resolution but low patient enrollment, and only 1 study of RYGB reported relevant data. No in-hospital or postoperative deaths were reported in any LAGB study. The most frequently reported complications for LAGB were band slippage and micronutrient deficiency with sporadic cases of band erosion, port/tube dysfunction, hiatal hernia, wound infection, and pouch dilation. More severe complications were reported for RYGB, such as pulmonary embolism, shock, intestinal obstruction, postoperative bleeding, staple line leak, and severe malnutrition. No in-hospital deaths were reported; however, 1 patient died 9 months after the study with severe Clostridium difficile colitis; 3 others died of causes not likely to have been directly related to the bariatric surgeries. No LAGB studies reported data on the impact of surgery on growth and development. One study of RYGB reported pre- and postoperative heights and concluded that there was no evidence of growth retardation at an average follow-up of 6 years, but it could not be determined from the data whether expected growth was achieved.

Table 11. Systematic Review Characteristics for Bariatric Surgery for Adolescents With Obesity

Study	Dates	Studies	Participants	Design	Duration
Qi et al. (2017)116	Jul 2017	49	RYGP: 1216 LAGB: 1028 LSG: 665 Other: 98	1 RCT 22 prospective 26 retrospective	12 to 120 mo
Black et al. (2013)117	Jan 2013	23	RYGP: 256 LAGB: 271 LSG: 90 Other: 20	1 controlled 22 uncontrolled	6 to 120 mo
Treadwell et al. (2008)118	Dec 2007	18	RYGB: 131 LAGB: 352 Other: 158	1 prospective 17 retrospective	0 to 22 y

LAGB: laparoscopic adjustable gastric banding; LSG: laparoscopic sleeve gastrectomy; RCT: randomized controlled trial; RYGP: Roux-en-Y gastric bypass.

Table 12. Systematic Review Results for Bariatric Surgery for Adolescents With Obesity

Study	BMI Reduction Mean Difference (95% CI)	Fasting Blood Insulin, mlU/L Mean Difference (95% CI)	Total Cholesterol, mg/dL Mean Difference (95% CI)
Qi et al. (2017)11
RYGP	18.5 (16.4 to 20.7)	24.8 (10.0 to 30.7)	29.4 (18.1 to 40.7)
LAGB	12.1 (11.0 to 13.3)	20.5 (16.4 to 24.6)	2.2 (-10.0 to 14.4)
LSG	16.0 (13.2 to 20.7)	18.4 (11.4 to 25.3)	13.6 (2.9 to 24.2)
Other	23.2 (15.6 to 30.7)	28.3 (5.7 to 50.9)	49.5 (29.9 to 69.2)
Black et al. (2013)117
RYGP	17.2 (14.3 to 20.1)	NR	NR
LAGB	10.5 (9.1 to 11.8)	NR	NR
LSG	14.5 (11.7 to 17.3)	NR	NR
Other	NR	NR	NR
Treadwell et al. (2008)118
RYGP	(17.8 to 22.3)a	NR	NR
LAGB	(10.6 to 13.7)a

BMI: body mass index; CI: confidence interval; LAGB: laparoscopic adjustable gastric banding; LSG: laparoscopic sleeve gastrectomy; NR: not reported; RYGP: Roux-en-Y gastric bypass. 
^a No point estimate provided; only 95% CIs given.

Observational Studies
Dumont et al. (2018) published a retrospective study of obese adolescents who underwent LAGB.¹¹⁹ Between 2006 and 2015, 97 consecutive teenagers (average age at surgery 17.2 ± 0.7 years; mean BMI of 44.9 ± 6.1 kg/m2) who had achieved full growth and sexual maturity and had previously failed a medical nutritional and dietary management program for at least 1 year were enrolled in the study. After a mean follow-up time of 56.0 ± 22.0 months, mean total weight loss was 20.0 ± 16.6% and mean excess weight loss was 46.6 ± 39.5%. Nineteen patients underwent band removal (mean 43.0 ± 28.0 months). No limitations to the study were reported.

One of the larger observational studies included in the systematic reviews was by Inge et al. (2014), who reported results from the Teen-Longitudinal Assessment of Bariatric Surgery study, a prospective, multicenter observational study of bariatric surgery in patients ages 19 or younger.¹²⁰ The study enrolled 242 patients, with a mean age of 17.1 years and median BMI of 50.5 kg/m2 (IQR, 45.2 to 58.2 kg/m2) at the time of surgery. All patients had at least 1 obesity-related comorbidity, most commonly dyslipidemia (74%), followed by OSA (57%), back and joint pain (46%), hypertension (45%), and fatty liver disease (37%). Gastric bypass, LAGB, and vertical SG were performed in 66.5%, 5.8%, and 27.7% of patients, respectively. Within 30 days of surgery, 20 major complications occurred in 19 (7.9%) patients, most of which were perioperative. The cohort is being followed to assess longer term outcomes.

Gastric Bypass
Comparative Studies
Olbers et al. (2017) published results from the Adolescent Morbid Obesity Surgery (AMOS) study.¹²¹ AMOS is a prospective, nonrandomized study of patients ages 13 to 18 years with severe obesity. Enrolled patients underwent RYGB (n = 81) and were compared with 80 matched adolescent controls undergoing conservative treatment and 81 matched adult controls undergoing RYGB. The primary outcome was change in BMI after 5 years. Adolescents undergoing RYGB had a mean age of 16.5 years and mean BMI of 45.5 kg/m2. At 5-year follow-up, adolescents receiving RYGB experienced a mean reduction in BMI of 13.1 kg/m2 (95% CI, 11.8 to 14.5). Adolescents receiving conservative treatment experienced a mean increase in BMI of 3.3 kg/m2 (95% CI, 1.1 to 4.8). Adult controls receiving RYGB experienced a reduction in BMI similar to the adolescents undergoing RYGB, 12.3 kg/m2 (95% CI, 10.9 to 13.7). Adolescents undergoing RYGB also experienced significant improvements in glucose, insulin, cholesterol, and blood pressure levels compared with adolescents in the control group.

Laparoscopic Adjustable Gastric Banding
Systematic Reviews
Willcox and Brennan (2014) conducted a systematic review focusing on studies reporting biopsychosocial outcomes following LAGB in adolescents with obesity.¹²² The literature search, conducted through May 2013, identified 11 studies for inclusion. Significant weight loss was reported in all studies. Resolution of comorbidities was also reported, though the evidence was poor quality due to a limited discussion of comorbidity assessment criteria. Reporting of psychosocial outcomes was considered limited, with reviewers concluding that further research is needed to better understand the behavioral, emotional, and social factors experienced by adolescents undergoing LAGB.

Randomized Controlled Trials
In the only RCT identified in the systematic reviews, O’Brien et al. (2010) reported on 50 adolescents between the ages of 14 and 18 years with a BMI 35 kg/m2 or higher who received either a lifestyle intervention or LAGB.¹²³ Follow-up was 2 years. Twenty-four of 25 patients in the gastric banding group and 18 of 25 in the lifestyle group completed the study. Twenty-one (84%) in the gastric banding group and 3 (12%) in the lifestyle group lost more than 50% of excess weight. Overall, mean weight loss in the gastric banding group was 34.6 kg (95% CI, 30.2 to 39.0), representing an EWL of 78.8% (95% CI, 66.6 to 91.0). Mean losses in the lifestyle group were 3.0 kg (95% CI, 2.1 to 8.1), representing an EWL of 13.2% (95% CI, 2.6 to 21.0). The gastric banding group experienced improved quality of life with no perioperative adverse events; however, 8 (33%) surgeries were required in 7 patients for revisional procedures, either for proximal pouch dilatation or tubing injury during follow-up.

Case Series
There are many case series of bariatric surgery in adolescents, and these series have generally reported weight loss in the same range reported for adults. For example, Nadler et al. (2008) reported on 73 patients ages 13 to 17 years who had undergone LAGB since 2001 at the authors’ institution.¹²⁴ Mean preoperative BMI was 48 kg/m2. EWL at 6 months, 1 year, and 2 years postoperatively was 35%, 57%, and 61%, respectively. Six patients developed band slippage, and 3 developed symptomatic hiatal hernias. Nutritional complications included an asymptomatic iron deficiency in 13 patients, asymptomatic vitamin D deficiency in 4 patients, and mild subjective hair loss in 14. In the 21 patients who entered the authors’ FDA-approved study and had reached 1-year follow-up, 51 comorbid conditions were identified, 35 of which completely resolved, 9 were improved, 5 were unchanged, and 2 were aggravated after 1 year.

Sleeve Gastrectomy
Manco et al. (2017) published results from contemporaneous cohorts of adolescent patients with a BMI of 35 kg/m2 or more and nonalcoholic steatohepatitis who chose between 3 treatment options.¹²⁵ Twenty patients chose to undergo LSG, 20 patients opted to ingest intragastric weight-loss devices (IGWLD, either the BioEnterics Intragastric Balloon System or Obalon Gastric Balloon) plus lifestyle interventions, and 53 patients chose lifestyle interventions alone. All patients in the LSG and IGWLD groups completed the study; 22 of the 53 in the lifestyle intervention group completed the study. After 1-year follow-up: patients undergoing LSG lost 21% body weight; patients treated with IGWLD lost 3% body weight, and patients receiving lifestyle interventions only gained 2% body weight. Nonalcoholic steatohepatitis reverted in 100% of patients receiving LSG and in 24% receiving IGWLD. Patients receiving lifestyle interventions alone did not improve significantly.

Alqahtani et al. (2021) conducted a prospective, noncomparative, cohort study analyzing durability of weight loss and comorbidity resolution, growth velocity, and adverse events associated with LSG in children and adolescents with severe obesity over 10 years.¹²⁶ Children and adolescents with class 2 or 3 obesity underwent LSG between 2008 and 2021. Overall, 2504 children and adolescents were included, with a mean age ± standard deviation (SD) 15.7 ± 3.7 years (range, 5 to 21 years) at the time of operation. In the 15- to 18-year age group specifically, there were 1517 children enrolled (61%). Mean ± SD baseline BMI was 44.8 ± 12.6 kg/m2, with a BMI z-score of 3.0 ± 0.5, representing 165% above the 95th percentile for age and sex, on average. In the overall cohort in the short- (1 to 3 years, n = 2051), medium- (4 to 6 years, n = 1268), and long-term (7 to 10 years, n = 632) follow-up, mean %EWL was 82.3% ± 20.5%, 76.3% ± 29.1%, and 71.1% ± 26.9%, respectively. At baseline, 263 patients (10.5%) were diagnosed with T2D, 227 (9.1%) were diagnosed with dyslipidemia, and 377 (15.1%) had hypertension. At long-term follow-up, complete comorbidity remission was observed in 74% of T2D cases, 59% of dyslipidemia cases, and 64% of hypertension cases. Mean height z-score change at short-, medium-, and long-term follow-up was 0.1 ± 0.5, 0.1 ± 1.2, and 0.0 ± 0.8, respectively, representing no significant change in growth velocity at each follow-up stage (p = .95, p = .21, and p = .40, respectively). There were 27 (1%) reported adverse events within the first 90 days after operation, including 2 patients with a staple line leak, 22 patients with nausea and vomiting, and 3 patients with signs of metabolic neuropathy, with no procedure-related mortality. None of those patients with adverse events had long-standing sequelae or disability.

Section Summary: Bariatric Surgery Adolescents
Gastric Bypass, Laparoscopic Adjustable Gastric Banding, or Sleeve Gastrectomy
Several systematic reviews and meta-analyses have been conducted on observational studies evaluating the use of bariatric surgery for the treatment of adolescents with obesity. There is an overlap of studies among the systematic reviews. The majority of evidence assesses the use of gastric bypass, SG, or LAGB. Two nonrandomized comparative studies were published after the systematic reviews. One compared RYGB with conservative treatment and with adults undergoing RYGB, and 1 compared LSG with gastric balloons and lifestyle interventions. The evidence on bariatric surgery in adolescents indicates that the percent EWL and change in BMI are approximately the same as that in adults. There are greater concerns for developmental maturity, psychosocial status, and informed consent in adolescents.

Bariatric Surgery Other Than Gastric Bypass, Laparoscopic Adjustable Gastric Banding, or Sleeve Gastrectomy
There is less evidence for the use of bariatric techniques other than gastric bypass, LAGB, and SG. Sample sizes are small for these other techniques and meta-analyses have shown wide CIs in the estimates.

Guideline recommendations for bariatric surgery in adolescents lack uniformity but generally correspond to the clinical selection criteria for adults and supplement these clinical selection criteria with greater attention to issues of maturity and psychosocial status.

Bariatric Surgery in Preadolescent Children
Review of Evidence
Alqahtani et al. (2021), described above, included children as young as 5 years of age in their prospective, noncomparative cohort study analyzing durability of weight loss and comorbidity resolution, growth velocity, and adverse events associated with LSG in children and adolescents with severe obesity over 10 years.¹²⁶ In the 5- to 14-year age group, 801 (32%) children were included. The mean percent of 95th percentile at baseline for children in this age group was 177% ± 38%. The %EWL after LSG in children aged 5 to 14 years was not significantly different from the adolescent children (> 14 years) as results were consistent across age groups. Additionally, the height z-score change did not differ in this age group, indicating no impact on change over 10 years of follow-up.

Black et al. (2013; described above) published a systematic review of 23 studies on bariatric surgery in children and adolescents.¹¹⁷

Section Summary: Bariatric Surgery in Preadolescent Children
There are few published data, and no studies were identified that focused on bariatric surgery solely in preadolescent children. A recently published (Alqahtani et al. [2021]) prospective noncomparative cohort study demonstrated substantial, long-lasting (follow-up of 10 years) weight loss and comorbidity resolution without safety concerns after LSG in children as young as 5 years of age. In the study of children and adolescents, 801/2504 (32%) children included were ages 5 to 14 years at the time of surgery. Additional comparative studies are needed to permit conclusions about the net health benefit of bariatric surgery in preadolescent children with obesity.

Hiatal Hernia Repair in Conjunction With Bariatric Surgery for Adults With Class 3 Obesity and a Preoperative Diagnosis of Hiatal Hernia
Clinical Context and Therapy Purpose
The purpose of hiatal hernia repair with bariatric surgery is to provide a treatment option that is an alternative to or an improvement on existing therapies, such as standard medical care, in patients with class 3 obesity and a preoperative diagnosis of hiatal hernia.

The following PICO was used to select literature to inform this review.

Populations
The relevant population of interest is individuals with class 3 obesity and a preoperative diagnosis of hiatal hernia.

Interventions
The therapy being considered is hiatal hernia repair with bariatric surgery.

Comparators
Comparators of interest include standard medical care. Treatment for patients with class 3 obesity and a preoperative diagnosis of hiatal hernia includes physical exercise, low carbohydrate dieting, and low-fat dieting.

Outcomes
The general outcomes of interest are OS, change in disease status, functional outcomes, health status measures, quality of life, treatment-related mortality, and treatment-related morbidity.

The existing literature evaluating hiatal hernia repair with bariatric surgery as a treatment for class 3 obesity and a preoperative diagnosis of hiatal hernia has varying lengths of follow-up, ranging from 1 to 3 years. While studies described below all reported at least 1 outcome of interest, longer follow-up was necessary to fully observe outcomes. One-year follow-up is necessary to demonstrate weight loss efficacy. Longer follow-up to 5 to 10 years is desirable to assess maintenance of weight loss, impact on co-occurring conditions, and appearance of long-term complications.

Study Selection Criteria
Methodologically credible studies were selected using the following principles:

• To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs.
• In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.
• To assess longer term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.
• Consistent with a "best available evidence approach," within each category of study design, studies with larger sample sizes and longer durations were sought.
• Studies with duplicative or overlapping populations were excluded.

Review of Evidence
Hiatal hernia is associated with obesity, and existing hiatal hernias may be worsened with bariatric surgery. In some studies, the presence of a hiatal hernia has been associated with complications after LAGB.¹²⁷ Although other studies have reported no differences in perioperative complications after LAGB in patients with and/or a hiatal hernia or those without and/or hiatal hernia.¹²⁸ Hiatal hernias, either incidentally found at surgery or diagnosed preoperatively, are often repaired at the time of bariatric surgery. In 2013, the Society of American Gastrointestinal and Endoscopic Surgeons published guidelines on the management of hiatal hernia, recommending that, during RYGB, SG, and the placement of LAGBs, all detected hiatal hernias should be repaired (grade of recommendation: weak; evidence quality moderate).¹²⁹ There is limited evidence regarding whether repair of hiatal hernias at the time of bariatric surgery improves outcomes after surgery; it consists primarily of cohort studies comparing outcomes for patients who had a hiatal hernia and underwent repair during bariatric surgery with patients without a hiatal hernia.

Systematic Reviews
Chen et al. (2021) published a systematic review of 18 studies that evaluated outcomes after hiatal hernia repair plus SG in obese patients (N = 937).¹³⁰ Results demonstrated that patients who underwent hiatal hernia repair during SG had significant reductions in BMI (MD, -11.42 kg/m2, 95% CI, -12.8 to -10.03), and the risk of symptoms (OR, 0.20; 95% CI, 0.10 to 0.41) and esophagitis (OR, 0.12; 95% CI, 0.05 to 0.26). Hiatal hernia repair during SG was superior to SG alone for remission (OR, 2.97; 95% CI, 1.78 to 4.95), but not de novo (OR, 0.61; 95% CI, 0.24 to 1.53). The pooled recurrence rate for hiatal hernia after hiatal hernia repair plus SG was 11% (95% CI, 4 to 19).

Section Summary: Hiatal Hernia Repair in Conjunction With Bariatric Surgery for Adults With Obesity and a Preoperative Diagnosis of Hiatal Hernia
Hiatal hernia repair is frequently undertaken at the time of bariatric surgery. The evidence related to whether hiatal hernia repair improves outcomes after bariatric surgery is limited, particularly for hiatal hernias that are incidentally diagnosed at the time of surgery. For patients with a preoperative diagnosis of a hiatal hernia, symptoms related to a hernia, and indications for surgical repair, it is reasonable to undertake this procedure at the time of bariatric surgery. For other patients, it is uncertain whether repair of a hiatal hernia at the time of bariatric surgery improves outcomes. A systematic review found that hiatal hernia repair during SG was superior to SG alone for remission, but not de novo.

The purpose of the following information is to provide reference material. Inclusion does not imply endorsement or alignment with the evidence review conclusions.

Clinical Input From Physician Specialty Societies and Academic Medical Centers
While the various physician specialty societies and academic medical centers may collaborate with and make recommendations during this process, through the provision of appropriate reviewers, input received does not represent an endorsement or position statement by the physician specialty societies or academic medical centers, unless otherwise noted.

Practice Guidelines and Position Statements
Guidelines or position statements will be considered for inclusion in Supplemental Information if they were issued by, or jointly by, a U.S. professional society, an international society with U.S. representation, or National Institute for Health and Care Excellence (NICE). Priority will be given to guidelines that are informed by a systematic review, include strength of evidence ratings, and include a description of management of conflict of interest.

American Association of Clinical Endocrinologists and American College of Endocrinology
In 2016, the American Association of Clinical Endocrinologists (AACE) and the American College of Endocrinology (ACE) jointly published comprehensive clinical guidelines on the medical care of individuals with obesity.¹ The guidelines addressed 9 broad clinical questions with 123 recommendations. The recommendations specific to bariatric surgery are shown in Table 13. The guidelines noted that a de novo evidence-based review of questions pertaining to bariatric surgery was not undertaken. Instead, the 2013 guidelines from AACE, the Obesity Society, and the American Society for Metabolic & Bariatric Surgery were reviewed and determined to be adequate. Key recommendations from those guidelines were included in the 2016 document and are shown in Table 13.

Table 13. Recommendations on Bariatric Surgery Included in the American Association of Clinical Endocrinologists and the American College of Endocrinology Guidelines for Medical Care of Patients With Obesity (2016)

Key Question	Recommendation	Evidence Grade	Best Evidence Level
9.1 Is bariatric surgery effective to treat obesity and weight-related complications?	R120. Patients with a BMI of >40 kg/m2 without coexisting medical problems and for whom the procedure would not be associated with excessive risk should be eligible for bariatric surgery	A	1
9.2 When should bariatric surgery be used to treat obesity and weight-related complications?	R121. Patients with a BMI of ≥ 35 kg/m2 and 1 or more severe obesity-related complications, including T2D, hypertension, obstructive sleep apnea, obesity hypoventilation syndrome, Pickwickian syndrome, nonalcoholic fatty liver disease or nonalcoholic steatohepatitis, pseudotumor cerebri, gastroesophageal reflux disease, asthma, venous stasis disease, severe urinary incontinence, debilitating arthritis, or considerably impaired QOL may also be considered for a bariatric surgery procedure. Patients with BMI of 30 to 34.9 kg/m2 with diabetes or metabolic syndrome may also be considered for a bariatric procedure, although current evidence is limited by the number of patients studied and lack of long-term data demonstrating net benefit.
	BMI ≥ 35 kg/m2 and therapeutic target of weight control and improved biochemical markers of CVD risk	A	1
	BMI ≥ 30 kg/m2 and therapeutic target of weight control and improved biochemical markers of CVD risk	B	2
	BMI ≥ 30 kg/m2 and therapeutic target of glycemic control in T2DM and improved biochemical markers of CVD risk	C	3
	R122. Independent of BMI criteria, there is insufficient evidence to recommend a bariatric surgical procedure specifically for glycemic control, lipid lowering, or CVD risk reduction alone	D	NA
	R123. All patients should undergo pre-operative evaluation for weight-related complications and causes of obesity, with special attention directed to factors that may affect a recommendation for bariatric surgery or be ameliorated by weight loss resulting from the procedure	A	1

BMI: body mass index; CVD: cardiovascular disease; NA: not applicable; QOL: quality of life; T2D: Type 2 diabetes.

American Academy of Clinical Endocrinologists, ACE, the Obesity Society, the American Society for Metabolic and Bariatric Surgery, Obesity Medicine Association, and American Society of Anesthesiologists
In 2019, an update of the joint 2013 guidelines on support for bariatric surgery patients were published by the AACE, the Obesity Society, the American Society for Metabolic and Bariatric Surgery (ASMBS), Obesity Medicine Association, and American Society of Anesthesiologists.¹³¹ Recommendations on the following questions are summarized below.

• “Which patients should be offered bariatric surgery?”
  • “Patients with a BMI [body mass index] ≥ 40 kg/m2 without coexisting medical problems and for whom bariatric surgery would not be associated with excessive risk should be eligible for a bariatric procedure.”
  • “Patients with a BMI ≥ 35 kg/m2 and 1 or more severe obesity-related complications remediable by weight loss, including T2D, high risk for T2D, poorly controlled hypertension, nonalcoholic fatty liver disease/nonalcoholic steatohepatitis, OSA [obstructive sleep apnea], osteoarthritis of the knee or hip, and urinary stress incontinence, should be considered for a bariatric procedure.”
  • "Patients with the following comorbidities and BMI≥ 35 kg/m2 may also be considered for a bariatric procedure, though the strength of evidence is more variable; obesity-hypoventilation syndrome and Pickwickian syndrome after a careful evaluation of operative risk; idiopathic intracranial hypertension; [gastroesophageal reflux disease]; severe venous stasis disease; impaired mobility due to obesity, and considerably impaired quality of life."
  • “Patients with BMI of 30 to 34.9 kg/m2 with T2D with inadequate glycemic control despite optimal lifestyle and medical therapy should be considered for a bariatric procedure; current evidence is insufficient to support recommending a bariatric procedure in the absence of obesity."
  • "The BMI criterion for bariatric procedures should be adjusted for ethnicity (e.g., 18.5 to 22.9 kg/m2 is normal range, 23 to 24.9 kg/m2 overweight, and ≥ 25 kg/m2 obesity for Asians)."
  • "Bariatric procedures should be considered to achieve optimal outcomes regarding health and quality of life when the amount of weight loss needed to prevent or treat clinically significant obesity-related complications cannot be obtained using only structured lifestyle change with medical therapy."
• “Which bariatric surgical procedure should be offered?”
  • “Selecting a bariatric procedure should be based on individualized goals of therapy (e.g., weight loss target and/or improvement in specific obesity-related complications), available local-regional expertise (obesity specialists, bariatric surgeon, and institution), patient preferences, personalized risk stratification, and other nuances as they become apparent. Notwithstanding technical surgical reasons, laparoscopic bariatric procedures should be preferred over open bariatric procedures due to lower early postoperative morbidity and mortality. Laparoscopic adjustable gastric banding, sleeve gastrectomy, RYGB [Roux-en-y gastric bypass], and LBPD/DS [laproscopic biliopancreatic diversion/duodenal switch], or related procedures should be considered as primary bariatric and metabolic procedures performed in patients requiring weight loss and/or amelioration of obesity-related complications. Physicians must exercise caution when recommending BPD [biliopancreatic diversion], BPD with duodenal switch, or related procedures because of the greater associated nutritional risks related to the increased length of bypassed small intestine. Newer nonsurgical bariatric procedures may be considered for selected patients who are expected to benefit from short-term (i.e., about 6 months) intervention with ongoing and durable structured lifestyle with/without medical therapy."

Individuals With Type 2 Diabetes Mellitus
In 2022, The AACE published updated guidelines for the comprehensive care of individuals with diabetes mellitus.¹³² Recommendations related to bariatric procedures are shown in Table 14.

Table 14. Recommendations on Bariatric Surgery Included in the American Association of Clinical Endocrinology Guidelines on Care of Persons With Diabetes Mellitus (2022)

Recommendation Number	Recommendation	Evidence Grade	Best Evidence Level
10.9	Persons with a BMI ≥ 35 kg/m2 and 1 or more severe obesity-related complications remediable by weight loss, including T2D, high risk for T2D (insulin resistance, prediabetes, and/or metabolic syndrome), poorly controlled hypertension, NAFLD/NASH, OSA, osteoarthritis of the knee or hip, and urinary stress incontinence, should be considered for a bariatric procedure	C	3
10.10	Persons with BMI 30 to 34.9 kg/m2 and T2D with inadequate glycemic control despite optimal lifestyle and medical therapy should be considered for a bariatric procedure	B	2

BEL: best evidence level; BMI: body mass index; GOE: grade of evidence; NAFLD: nonalcoholic fatty liver disease; NASH: nonalcoholic steatohepatitis; OSA: obstructive sleep apnea; T2D: Type 2 diabetes.

Veterans Affairs/Department of Defense
In 2020, the Department of Veterans Affairs/Department of Defense (VA/DoD) published a clinical practice guideline for the management of adult overweight and obesity.133, Recommendations on bariatric surgery are shown in Table 15

Table 15. Recommendations on Bariatric Surgery Included in VA/DoD Obesity Treatment Guidelines (2020)

Recommendation Number	Recommendation Statement	Strength of Evidence1
12	We suggest offering the option of metabolic/bariatric surgery, in conjunction with a comprehensive lifestyle intervention, to patients with a body mass index of ≥ 30 kg/m2 and Type 2 diabetes mellitus.	Weak
13	We suggest offering the option of metabolic/bariatric surgery, in conjunction with a comprehensive lifestyle intervention, for long-term weight loss/maintenance and/or to improve obesity-associated condition(s) in adult patients with a body mass index ≥ 40 kg/m2 or those with body mass index ≥ 35 kg/m2 with obesity-associated condition(s).	Weak
14	There is insufficient evidence to recommend for or against metabolic/bariatric surgery to patients over age 65.	Neither for nor against
15	There is insufficient evidence to recommend for or against percutaneous gastrostomy devices for weight loss in patients with obesity.	Neither for nor against
16	We suggest offering intragastric balloons in conjunction with a comprehensive lifestyle intervention to patients with obesity (body mass index ≥ 30 kg/m2 ) who prioritize short-term (up to six months) weight loss.	Weak
17	There is insufficient evidence to recommend for or against intragastric balloons for long-term weight loss to support chronic weight management or maintenance.	Neither for nor against

¹ The relative strength of the recommendation is based on a binary scale, “Strong” or “Weak.” A strong recommendation indicates that the Work Group is highly confident that desirable outcomes outweigh undesirable outcomes. If the Work Group is less confident of the balance between desirable and undesirable outcomes, they present a weak recommendation.

Society of American Gastrointestinal and Endoscopic Surgeons
In 2013, the Society of American Gastrointestinal and Endoscopic Surgeons issued evidence-based guidelines on the management of a hiatal hernia, which included a recommendation about the repair of hiatal hernias incidentally detected at the time of bariatric surgery.¹²⁹ These guidelines stated: “During operations for Roux-en-Y gastric bypass, sleeve gastrectomy and the placement of adjustable gastric bands, all detected hiatal hernias should be repaired” (moderate quality evidence, weak recommendation).

Guidelines for Children and Adolescents
Childerhose et al. (2017) conducted a systematic review of adolescent bariatric surgery recommendation documents published in the United States and provided recommendations based on their review.¹³⁴ The literature search was conducted from 1999 through 2013 and identified 16 recommendations for inclusion: 10 clinical practice guidelines, 4 position statements, and 2 consensus statements. Fifteen of the 16 publications recommended bariatric surgery for adolescents. The main reasons for recommending bariatric surgery for adolescents included: (1) surgery is effective in producing short- and long-term weight loss; (2) surgery is appropriate when the patient does not respond to behavioral or medical interventions; (3) surgery is appropriate when serious comorbidities threaten the health of the patient; and (4) surgery can improve long-term health and/or emotional problems. Body mass index thresholds ranged from 35 kg/m2 or more to 50 kg/m2 or more, with lower thresholds usually requiring the presence of at least 1 serious comorbidity. The minimum age was specified in 10 publications, with most using physiologic maturity (Tanner stage IV and/or 95% of adult height based on bone age, corresponding to ≥ 13 years for females and to ≥ 15 years for males) rather than years.

American Academy of Pediatrics
In 2019, the American Academy of Pediatrics (AAP) published a report outlining the current evidence regarding adolescent bariatric surgery that provided recommendations for practitioners and policy makers.¹³⁵ Within this report, AAP listed indications for adolescent metabolic and bariatric surgery that reflected 2018 ASMBS recommendations. Additionally, the AAP report noted that generally accepted contraindications to bariatric surgery included: "a medically correctable cause of obesity, untreated or poorly controlled substance abuse, concurrent or planned pregnancy, current eating disorder, or inability to adhere to postoperative recommendations and mandatory lifestyle changes."

In 2023, the AAP published their first evidence-based clinical practice guideline for the evaluation and treatment of children and adolescents (ages 2 to 18 years) with obesity.¹³⁶ The recommendations put forth in the guideline are based on evidence from RCTs and comparative effectiveness trials, along with high-quality longitudinal and epidemiologic studies gathered in a systematic review process described in their methodology. The AAP's recommendation related to bariatric surgery is below:

• "Pediatricians and other PHCPs [pediatric health care providers] should offer referral for adolescents 13 years and older with severe obesity (BMI ≥ 120% of the 95th percentile for age and sex) for evaluation for metabolic and bariatric surgery to local or regional comprehensive multidisciplinary pediatric metabolic and bariatric surgery centers (Grade C Evidence Quality)."

They list indications for adolescent metabolic and bariatric surgery (Table 16) that align with the 2019 indications.

Table 16. Indications for Adolescent Metabolic and Bariatric Surgery

Weight Criteria	Comorbid Conditions
Class 2 obesity; BMI ≥ 35, or 120% of the 95th percentile for age and sex, whichever is lower Class 3 obesity; BMI ≥ 40, or 140% of the 95th percentile for age and sex, whichever is lower	Clinically significant disease, including, but not limited to, OSA (AHI >5), T2D, IIH, NASH, Blount disease, SCFE, depressed health-related quality of life, and hypertension Not required but commonly present

AHI: apnea-hypopnea index; BMI: body mass index; IIH: idiopathic intracranial hypertension; NASH: non-alcoholic steatohepatitis; OSA: obstructive sleep apnea; SCFE: slipped capital femoral epiphysis; T2D: Type 2 diabetes.

American Society for Metabolic and Bariatric Surgery
In 2012, the ASMBS best practice guidelines found that current evidence was insufficient to discriminate among specific bariatric procedures, but allowed that there was an increasing body of data showing safety and efficacy of Roux-en-Y gastric bypass and adjustable gastric band for the pediatric population.¹³⁷ Bariatric surgery was recommended for pediatric patients with morbid obesity and the following comorbidities:

• Strong indications: T2D, moderate or severe obstructive sleep apnea (apnea-hypopnea index >15), nonalcoholic steatohepatitis, pseudotumor cerebri.
• Less strong indications: cardiovascular disease, metabolic syndrome.

The guidelines stated that depression and eating disorders should not be considered exclusion criteria for bariatric surgery. The guidelines also noted that depression should be monitored following the procedure and that eating disorders should be treated and the patient stabilized before the procedure.

In 2018, ASBMS published an update to the 2012 guideline.¹³⁸ Summary of major changes in the guideline included:

• "Vertical sleeve gastrectomy has become the most used and most recommended operation in adolescents with severe obesity for several reasons, near-equivalent weight loss to RYGB in adolescents, fewer reoperations, better iron absorption, and near-equivalent effect on comorbidities as RYGB in adolescents. However, given the more extensive long-term data available for RYGB, we can recommend the use of either RYGB or VSG in adolescents. Long-term outcomes of after vertical sleeve gastrectomy are still not well understood."
• "There are no data that the number of preoperative weight loss attempts correlated with success after metabolic/bariatric surgery. Compliance with a multidisciplinary preoperative program may improve outcomes after metabolic/bariatric surgery but prior attempts at weight loss should be removed as a barrier to definitive treatment for obesity."
• "The use of the most up to date definitions of childhood obesity are as follows: (1) BMI cut offs of 35 kg/m2 or 120% of the 95th percentile with a comorbidity, or (2) BMI >40 kg/m2 or 140% of the 95th percentile without a comorbidity (whichever is less). Requiring adolescents with a BMI >40 to have a comorbidity (as in the old guidelines) puts children at a significant disadvantage to attaining a healthy weight. Earlier surgical intervention (at a BMI <45 kg/m2) can allow adolescents to reach a normal weight and avoid lifelong medication therapy and end organ damage from comorbidities."
• "Certain comorbidities should be considered in adolescents, specifically the psychosocial burden of obesity, the orthopedic diseases specific to children, , and cardiac risk factors. Given the poor outcomes of medical therapies for T2D in children, these comorbidities may be considered an indication for metabolic/bariatric surgery in younger adolescents or those with lower obesity percentiles."
• "Vitamin B deficiencies, especially B1 appear to be more common in adolescents both preoperatively and postoperatively; they should be screened for and treated. Prophylactic B1 for the first 6 months postoperatively is recommended as is education of patients and primary care providers on the signs and symptoms of common deficiencies."
• "Developmental delay, autism spectrum, or syndromic obesity should not be a contraindication to metabolic/bariatric surgery. Each patient and caregiver team will need to be assessed for the ability to make dietary and lifestyle changes required for surgery. Multidisciplinary teams should agree on the specific needs and abilities of the given patient and caregiver and these should be considered on a case-by-case basis with the assistance of the hospital ethics committee where appropriate."
• "Because metabolic/bariatric surgery results in better weight loss and resolution of comorbidities in adolescents at lower BMI’s with fewer comorbidities, referrals should occur early, as soon as a child is recognized to suffer from severe obesity disease (BMI > 120% of the 95th percentile or BMI of 35). Prior weight loss attempts, Tanner stage, and bone age should not be considered when referring patients to a metabolic/bariatric surgery program."
• "Unstable family environments, eating disorders, mental illness, or prior trauma should not be considered contraindications for metabolic/bariatric surgery in adolescents; however, these should be optimized and treated where possible before and surrounding any surgical intervention for obesity."

In 2022, the ASMBS updated their guideline on indications for metabolic and bariatric surgery.¹³⁹ They noted that prospective data demonstrated durable weight loss and maintained co-morbidity remission in patients as young as 5 years of age. Additionally, the ASMBS stated that metabolic and bariatric surgery do not negatively impact pubertal development or linear growth, and therefore a specific Tanner stage and bone age should not be considered a requirement for surgery. Other statements supported 2018 recommendations, including that syndromic obesity, developmental delay, autism spectrum, or a history of trauma would not be considered a contraindication to bariatric surgery in children or adolescents.

Endocrine Society
In 2008, the Endocrine Society published recommendations on the prevention and treatment of pediatric obesity.¹⁴⁰ In 2017, the Society sponsored an update of these guidelines by the Pediatric Endocrine Society and the European Society of Endocrinology.¹⁴¹ These guidelines recommended the following:

“We suggest that bariatric surgery be considered only under the following conditions:

• The child has attained Tanner 4 or 5 pubertal development and final or near-final adult height.
• The child has a BMI > 40 kg/m2 or has BMI above 35 kg/m2 and significant, extreme comorbidities.
• Extreme obesity and comorbidities persist, despite compliance with a formal program of lifestyle modification, with or without a trial of pharmacotherapy.
• Psychological evaluation confirms the stability and competence of the family unit.
• There is access to an experienced surgeon in a pediatric bariatric surgery center of excellence that provides the necessary infrastructure for patient care, including a team capable of long-term follow-up of the metabolic and psychosocial needs of the patient and family.
• The patient demonstrates the ability to adhere to the principles of healthy dietary and activity habits.

We recommend against bariatric surgery for preadolescent children, for pregnant or breast-feeding adolescents (and those planning to become pregnant within 2 yr of surgery) and in any patient who has not mastered the principles of healthy dietary and activity habits and/or has an unresolved substance abuse, eating disorder, or untreated psychiatric disorder.”

U.S. Preventive Services Task Force Recommendations
Not applicable

Ongoing and Unpublished Clinical Trials
Some currently ongoing and unpublished trials that might influence this review are listed in Table 17.

Table 17. Summary of Key Trials

NCT No.	Trial Name	Planned Enrollment	Completion Date
Ongoing
NCT02390973a	Surgery Versus Best Medical Management for the Long Term Remission of Type 2 Diabetes and Related Diseases (REMISSION)	408	Mar 2024
NCT02328599	A Prospective Consortium Evaluating the Long-term Follow-up of Patients With Type 2 Diabetes Enrolled In a Randomized Controlled Trial Comparing Bariatric Surgery Versus Medical Management (ARMMS-T2D)	302	Jun 2031
NCT03610256	Prospective Multicentric Randomized Trial Comparing the Efficacy and Safety of single anastomosis- Duodeno Ileal Bypass With Sleeve Gastrectomy (SADI-S) Versus Roux-en-Y Gastric Bypass (RYGB) (SADISLEEVE)	382	Dec 2031
NCT03517072	Determinants of the Long-Term Success of Bariatric Surgery	1000	Jan 2 2024
NCT03472157	Prospective Multicentric, Open Label, Randomized Clinical Trial of Superiority, With Two Arms, Comparing Bariatric Surgery to the Recommended Medical Treatment for NASH (NASHSURG)	100	Mar 2026
NCT04506190	A Prospective Multicenter Study to Evaluate the Perioperative Outcomes of Laparoscopic and Robotic-Assisted Revisional Bariatric Surgery	100	Sep 2024
NCT04128995	Surgical or Medical Treatment for Pediatric Type 2 Diabetes	100	Sep 2025
NCT03236142	The Single, 300 cm Loop, Duodenal Switch (SIPS) Results in Less Nutritional Deficiencies Than the Standard Duodenal Switch (DS) Operation: A Multicenter, Randomized Controlled Trial	110	Jan 2025
NCT02692469	Laparoscopic single anastomosis- Duodenal-Jejunal Bypass With Sleeve Gastrectomy vs Laparoscopic Duodenal Switch as a Primary Bariatric Procedure. 5 Year Patient Follow	140	Apr 2026
NCT04165694	Single Anastomosis Duodenal Ileal Bypass (SADI) as a Second Stage for Sleeve Gastrectomy Weight Loss Failure	54	Dec 2030
NCT01172899	The BASIC Trial. Morbid Obesity in Children and Adolescents: a Prospective Randomised Trial of Conservative Treatment Versus Surgery	60	Dec 2022 (unknown status)

NCT: national clinical trial.
^a Denotes industry-sponsored or cosponsored trial.

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71. Strain GW, Torghabeh MH, Gagner M, et al. Nutrient Status 9 Years After Biliopancreatic Diversion with Duodenal Switch (BPD/DS): an Observational Study. Obes Surg. Jul 2017; 27(7): 1709-1718. PMID 28155056
72. Marceau P, Biron S, Hould FS, et al. Duodenal switch improved standard biliopancreatic diversion: a retrospective study. Surg Obes Relat Dis. Jan-Feb 2009;5(1):43-47. PMID 18440876
73. Yan Y, Sha Y, Yao G, et al. Roux-en-Y Gastric Bypass Versus Medical Treatment for Type 2 Diabetes Mellitus in Obese Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Medicine (Baltimore). Apr 2016; 95(17): e3462. PMID 27124041
74. Wu GZ, Cai B, Yu F, et al. Meta-analysis of bariatric surgery versus non-surgical treatment for type 2 diabetes mellitus. Oncotarget. Dec 27 2016; 7(52): 87511-87522. PMID 27626180
75. Cummings DE, Cohen RV. Bariatric/Metabolic Surgery to Treat Type 2 Diabetes in Patients With a BMI 35 kg/m2. Diabetes Care. Jun 2016; 39(6): 924-33. PMID 27222550
76. Cummings DE, Rubino F. Metabolic surgery for the treatment of type 2 diabetes in obese individuals. Diabetologia. Feb 2018; 61(2): 257-264. PMID 29224190
77. Muller-Stich BP, Senft JD, Warschkow R, et al. Surgical versus medical treatment of type 2 diabetes mellitus in nonseverely obese patients: a systematic review and meta-analysis. Ann Surg. Mar 2015;261(3):421-429. PMID 25405560
78. Rao WS, Shan CX, Zhang W, et al. A meta-analysis of short-term outcomes of patients with type 2 diabetes mellitus and BMI </ = 35 kg/m2 undergoing Roux-en-Y gastric bypass. World J Surg. Jan 2015;39(1):223-230. PMID 25159119
79. Simonson DC, Vernon A, Foster K, et al. Adjustable gastric band surgery or medical management in patients with type 2 diabetes and obesity: three-year results of a randomized trial. Surg Obes Relat Dis. Dec 2019; 15(12): 2052-2059. PMID 31931977
80. Ikramuddin S, Billington CJ, Lee WJ, et al. Roux-en-Y gastric bypass for diabetes (the Diabetes Surgery Study): 2-year outcomes of a 5-year, randomised, controlled trial. Lancet Diabetes Endocrinol. Jun 2015; 3(6): 413-422. PMID 25979364
81. Liang Z, Wu Q, Chen B, et al. Effect of laparoscopic Roux-en-Y gastric bypass surgery on type 2 diabetes mellitus with hypertension: a randomized controlled trial. Diabetes Res Clin Pract. Jul 2013;101(1):50-56. PMID 23706413
82. Courcoulas AP, Belle SH, Neiberg RH, et al. Three-Year Outcomes of Bariatric Surgery vs Lifestyle Intervention for Type 2 Diabetes Mellitus Treatment: A Randomized Clinical Trial. JAMA Surg. Oct 2015; 150(10): 931-40. PMID 26132586
83. Courcoulas AP, Gallagher JW, Neiberg RH, et al. Bariatric Surgery vs Lifestyle Intervention for Diabetes Treatment: 5-Year Outcomes From a Randomized Trial. J Clin Endocrinol Metab. Mar 01 2020; 105(3): 866-76. PMID 31917447
84. Schauer PR, Bhatt DL, Kirwan JP, et al. Bariatric Surgery versus Intensive Medical Therapy for Diabetes - 5-Year Outcomes. N Engl J Med. Feb 16 2017; 376(7): 641-651. PMID 28199805
85. Mingrone G, Panunzi S, De Gaetano A, et al. Bariatric-metabolic surgery versus conventional medical treatment in obese patients with type 2 diabetes: 5 year follow-up of an open-label, single-centre, randomised controlled trial. Lancet. Sep 05 2015; 386(9997): 964-73. PMID 26369473
86. Wentworth JM, Playfair J, Laurie C, et al. Multidisciplinary diabetes care with and without bariatric surgery in overweight people: a randomised controlled trial. Lancet Diabetes Endocrinol. Jul 2014;2(7):545-552. PMID 24731535
87. Halperin F, Ding SA, Simonson DC, et al. Roux-en-Y gastric bypass surgery or lifestyle with intensive medical management in patients with type 2 diabetes: feasibility and 1-year results of a randomized clinical trial. JAMA Surg. Jul 2014;149(7):716-726. PMID 24899464
88. Technology Evaluation Center (TEC). Laparoscopic adjustable gastric banding in patients with body mass index less than 35 kg/m2 with weight-related comorbidity. TEC Assessments. 2012;Volume 27:Tab 3.
89. Slater GH, Ren CJ, Siegel N, et al. Serum fat-soluble vitamin deficiency and abnormal calcium metabolism after malabsorptive bariatric surgery. J Gastrointest Surg. Jan 2004;8(1):48-55; discussion 54-45. PMID 14746835
90. Dolan K, Hatzifotis M, Newbury L, et al. A clinical and nutritional comparison of biliopancreatic diversion with and without duodenal switch. Ann Surg. Jul 2004;240(1):51-56. PMID 15213618
91. Technology Evaluation Center (TEC). TEC Special Report: The relationship between weight loss and changes in morbidity following bariatric surgery for morbid obesity. TEC Assessments. 2003;Vol 18:Tab 18.
92. Coffin B, Maunoury V, Pattou F, et al. Impact of Intragastric Balloon Before Laparoscopic Gastric Bypass on Patients with Super Obesity: a Randomized Multicenter Study. Obes Surg. Apr 2017; 27(4): 902-909. PMID 27664095
93. Cottam D, Qureshi FG, Mattar SG, et al. Laparoscopic sleeve gastrectomy as an initial weight-loss procedure for high-risk patients with morbid obesity. Surg Endosc. Jun 2006;20(6):859-863. PMID 16738970
94. Alexandrou A, Felekouras E, Giannopoulos A, et al. What is the actual fate of super-morbid-obese patients who undergo laparoscopic sleeve gastrectomy as the first step of a two-stage weight-reduction operative strategy? Obes Surg. Jul 26 2012;22(10):1623-1628. PMID 22833137
95. Silecchia G, Rizzello M, Casella G, et al. Two-stage laparoscopic biliopancreatic diversion with duodenal switch as treatment of high-risk super-obese patients: analysis of complications. Surg Endosc. May 2009;23(5):1032-1037. PMID 18814005
96. Li H, Wang J, Wang W, et al. Comparison Between Laparoscopic Sleeve Gastrectomy and Laparoscopic Greater Curvature Plication Treatments for Obesity: an Updated Systematic Review and Meta-Analysis. Obes Surg. Sep 2021; 31(9): 4142-4158. PMID 34227019
97. Sullivan S, Swain JM, Woodman G, et al. Randomized sham-controlled trial evaluating efficacy and safety of endoscopic gastric plication for primary obesity: The ESSENTIAL trial. Obesity (Silver Spring). Feb 2017; 25(2): 294-301. PMID 28000425
98. Shoar S, Poliakin L, Rubenstein R, et al. Single Anastomosis Duodeno-Ileal Switch (SADIS): A Systematic Review of Efficacy and Safety. Obes Surg. Jan 2018; 28(1): 104-113. PMID 28823074
99. Torres A, Rubio MA, Ramos-Leví AM, et al. Cardiovascular Risk Factors After Single Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy (SADI-S): a New Effective Therapeutic Approach?. Curr Atheroscler Rep. Nov 07 2017; 19(12): 58. PMID 29116413
100. Rohde U, Hedback N, Gluud LL, et al. Effect of the EndoBarrier Gastrointestinal Liner on obesity and type 2 diabetes: a systematic review and meta-analysis. Diabetes Obes Metab. Mar 2016; 18(3): 300-5. PMID 26537317
101. Courcoulas A, Abu Dayyeh BK, Eaton L, et al. Intragastric balloon as an adjunct to lifestyle intervention: a randomized controlled trial. Int J Obes (Lond). Mar 2017; 41(3): 427-433. PMID 28017964
102. Genco A, Cipriano M, Bacci V, et al. BioEnterics Intragastric Balloon (BIB): a short-term, double-blind, randomised, controlled, crossover study on weight reduction in morbidly obese patients. Int J Obes (Lond). Jan 2006;30(1):129-133. PMID 16189503
103. Kotzampassi K, Grosomanidis V, Papakostas P, et al. 500 intragastric balloons: what happens 5 years thereafter? Obes Surg. Jun 2012;22(6):896-903. PMID 22287051
104. Saber AA, Shoar S, Almadani MW, et al. Efficacy of First-Time Intragastric Balloon in Weight Loss: a Systematic Review and Meta-analysis of Randomized Controlled Trials. Obes Surg. Feb 2017; 27(2): 277-287. PMID 27465936
105. Moura D, Oliveira J, De Moura e.g., et al. Effectiveness of intragastric balloon for obesity: A systematic review and meta-analysis based on randomized control trials. Surg Obes Relat Dis. Feb 2016; 12(2): 420-9. PMID 26968503
106. Zheng Y, Wang M, He S, et al. Short-term effects of intragastric balloon in association with conservative therapy on weight loss: a meta-analysis. J Transl Med. Jul 29 2015; 13: 246. PMID 26219459
107. Kotinda APST, de Moura DTH, Ribeiro IB, et al. Efficacy of Intragastric Balloons for Weight Loss in Overweight and Obese Adults: a Systematic Review and Meta-analysis of Randomized Controlled Trials. Obes Surg. Jul 2020; 30(7): 2743-2753. PMID 32300945
108. Thompson CC, Abu Dayyeh BK, Kushner R, et al. Percutaneous Gastrostomy Device for the Treatment of Class II and Class III Obesity: Results of a Randomized Controlled Trial. Am J Gastroenterol. Mar 2017; 112(3): 447-457. PMID 27922026
109. Noren E, Forssell H. Aspiration therapy for obesity; a safe and effective treatment. BMC Obes. 2016; 3: 56. PMID 28035287
110. Matar R, Monzer N, Jaruvongvanich V, et al. Indications and Outcomes of Conversion of Sleeve Gastrectomy to Roux-en-Y Gastric Bypass: a Systematic Review and a Meta-analysis. Obes Surg. Sep 2021; 31(9): 3936-3946. PMID 34218416
111. Parmar CD, Gan J, Stier C, et al. One Anastomosis/Mini Gastric Bypass (OAGB-MGB) as revisional bariatric surgery after failed primary adjustable gastric band (LAGB) and sleeve gastrectomy (SG): A systematic review of 1075 patients. Int J Surg. Sep 2020; 81: 32-38. PMID 32738545
112. Brethauer SA, Kothari S, Sudan R, et al. Systematic review on reoperative bariatric surgery: American Society for Metabolic and Bariatric Surgery Revision Task Force. Surg Obes Relat Dis. Sep-Oct 2014;10(5):952-972. PMID 24776071
113. Dang JT, Vaughan T, Mocanu V, et al. Conversion of Sleeve Gastrectomy to Roux-en-Y Gastric Bypass: Indications, Prevalence, and Safety. Obes Surg. May 2023; 33(5): 1486-1493. PMID 36922465
114. Petrucciani N, Martini F, Benois M, et al. Revisional One Anastomosis Gastric Bypass with a 150-cm Biliopancreatic Limb After Failure of Adjustable Gastric Banding: Mid-Term Outcomes and Comparison Between One- and Two-Stage Approaches. Obes Surg. Dec 2021; 31(12): 5330-5341. PMID 34609712
115. Almalki OM, Lee WJ, Chen JC, et al. Revisional Gastric Bypass for Failed Restrictive Procedures: Comparison of Single-Anastomosis (Mini-) and Roux-en-Y Gastric Bypass. Obes Surg. Apr 2018; 28(4): 970-975. PMID 29101719
116. Sudan R, Nguyen NT, Hutter MM, et al. Morbidity, mortality, and weight loss outcomes after reoperative bariatric surgery in the USA. J Gastrointest Surg. Jan 2015;19(1):171-178; discussion 178-179. PMID 25186073
117. Catalano MF, Rudic G, Anderson AJ, et al. Weight gain after bariatric surgery as a result of a large gastric stoma: endotherapy with sodium morrhuate may prevent the need for surgical revision. Gastrointest Endosc. Aug 2007;66(2):240-245. PMID 17331511
118. Herron DM, Birkett DH, Thompson CC, et al. Gastric bypass pouch and stoma reduction using a transoral endoscopic anchor placement system: a feasibility study. Surg Endosc. Apr 2008;22(4):1093-1099. PMID 18027049
119. Thompson CC, Slattery J, Bundga ME, et al. Peroral endoscopic reduction of dilated gastrojejunal anastomosis after Roux-en-Y gastric bypass: a possible new option for patients with weight regain. Surg Endosc. Nov 2006;20(11):1744-1748. PMID 17024527
120. Eid GM, McCloskey CA, Eagleton JK, et al. StomaphyX vs a sham procedure for revisional surgery to reduce regained weight in Roux-en-Y gastric bypass patients: a randomized clinical trial. JAMA Surg. Apr 2014;149(4):372-379. PMID 24554030
121. Dakin GF, Eid G, Mikami D, et al. Endoluminal revision of gastric bypass for weight regain--a systematic review. Surg Obes Relat Dis. May-Jun 2013;9(3):335-342. PMID 23561960
122. Cohen RV, Oliveira da Costa MV, Charry L, et al. Endoscopic gastroplasty to treat medically uncontrolled obesity needs more quality data: A systematic review. Surg Obes Relat Dis. Jul 2019; 15(7): 1219-1224. PMID 31130406
123. Qi L, Guo Y, Liu CQ, et al. Effects of bariatric surgery on glycemic and lipid metabolism, surgical complication and quality of life in adolescents with obesity: a systematic review and meta-analysis. Surg Obes Relat Dis. Dec 2017; 13(12): 2037-2055. PMID 29079384
124. Black JA, White B, Viner RM, et al. Bariatric surgery for obese children and adolescents: a systematic review and meta-analysis. Obes Rev. Aug 2013;14(8):634-644. PMID 23577666
125. Treadwell JR, Sun F, Schoelles K. Systematic review and meta-analysis of bariatric surgery for pediatric obesity. Ann Surg. Nov 2008;248(5):763-776. PMID 18948803
126. Dumont PN, Blanchet MC, Gignoux B, et al. Medium- to Long-Term Outcomes of Gastric Banding in Adolescents: a Single-Center Study of 97 Consecutive Patients. Obes Surg. Jan 2018; 28(1): 285-289. PMID 29103071
127. Inge TH, Zeller MH, Jenkins TM, et al. Perioperative outcomes of adolescents undergoing bariatric surgery: the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study. JAMA Pediatr. Jan 2014;168(1):47-53. PMID 24189578
128. Olbers T, Beamish AJ, Gronowitz E, et al. Laparoscopic Roux-en-Y gastric bypass in adolescents with severe obesity (AMOS): a prospective, 5-year, Swedish nationwide study. Lancet Diabetes Endocrinol. Mar 2017; 5(3): 174-183. PMID 28065734
129. Willcox K, Brennan L. Biopsychosocial outcomes of laparoscopic adjustable gastric banding in adolescents: a systematic review of the literature. Obes Surg. Sep 2014;24(9):1510-1519. PMID 24849913
130. O'Brien PE, Sawyer SM, Laurie C, et al. Laparoscopic adjustable gastric banding in severely obese adolescents: a randomized trial. JAMA. Feb 10 2010;303(6):519-526. PMID 20145228
131. Nadler EP, Youn HA, Ren CJ, et al. An update on 73 US obese pediatric patients treated with laparoscopic adjustable gastric banding: comorbidity resolution and compliance data. J Pediatr Surg. Jan 2008;43(1):141-146. PMID 18206472
132. Manco M, Mosca A, De Peppo F, et al. The Benefit of Sleeve Gastrectomy in Obese Adolescents on Nonalcoholic Steatohepatitis and Hepatic Fibrosis. J Pediatr. Jan 2017; 180: 31-37.e2. PMID 27697327
133. Alqahtani AR, Elahmedi M, Abdurabu HY, et al. Ten-Year Outcomes of Children and Adolescents Who Underwent Sleeve Gastrectomy: Weight Loss, Comorbidity Resolution, Adverse Events, and Growth Velocity. J Am Coll Surg. Dec 2021; 233(6): 657-664. PMID 34563670
134. Greenstein RJ, Nissan A, Jaffin B. Esophageal anatomy and function in laparoscopic gastric restrictive bariatric surgery: implications for patient selection. Obes Surg. Apr 1998;8(2):199-206. PMID 9730394
135. Pilone V, Vitiello A, Hasani A, et al. Laparoscopic adjustable gastric banding outcomes in patients with gastroesophageal reflux disease or hiatal hernia. Obes Surg. Feb 2015;25(2):290-294. PMID 25030091
136. Kohn GP, Price RR, DeMeester SR, et al. Guidelines for the management of hiatal hernia. Surg Endosc. Dec 2013;27(12):4409-4428. PMID 24018762
137. Chen W, Feng J, Wang C, et al. Effect of Concomitant Laparoscopic Sleeve Gastrectomy and Hiatal Hernia Repair on Gastroesophageal Reflux Disease in Patients with Obesity: a Systematic Review and Meta-analysis. Obes Surg. Sep 2021; 31(9): 3905-3918. PMID 34254259
138. Mechanick JI, Apovian C, Brethauer S, et al. CLINICAL PRACTICE GUIDELINES FOR THE PERIOPERATIVE NUTRITION, METABOLIC, AND NONSURGICAL SUPPORT OF PATIENTS UNDERGOING BARIATRIC PROCEDURES - 2019 UPDATE: COSPONSORED BY AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS/AMERICAN COLLEGE OF ENDOCRINOLOGY, THE OBESITY SOCIETY, AMERICAN SOCIETY FOR METABOLIC BARIATRIC SURGERY, OBESITY MEDICINE ASSOCIATION, AND AMERICAN SOCIETY OF ANESTHESIOLOGISTS - EXECUTIVE SUMMARY. Endocr Pract. Dec 2019; 25(12): 1346-1359. PMID 31682518
139. Blonde L, Umpierrez GE, Reddy SS, et al. American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update. Endocr Pract. Oct 2022; 28(10): 923-1049. PMID 35963508
140. Department of Veterans Affairs/Department of Defense. Clinical Practice Guidelines. Management of Adult Overweight and Obesity (OBE) (2020). https://www.healthquality.va.gov/guidelines/CD/obesity/. Accessed April 2, 2024
141. Childerhose JE, Alsamawi A, Mehta T, et al. Adolescent bariatric surgery: a systematic review of recommendation documents. Surg Obes Relat Dis. Oct 2017; 13(10): 1768-1779. PMID 28958402
142. Armstrong SC, Bolling CF, Michalsky MP, et al. Pediatric Metabolic and Bariatric Surgery: Evidence, Barriers, and Best Practices. Pediatrics. Dec 2019; 144(6). PMID 31656225
143. Hampl SE, Hassink SG, Skinner AC, et al. Clinical Practice Guideline for the Evaluation and Treatment of Children and Adolescents With Obesity. Pediatrics. Jan 09 2023. PMID 36622115
144. Michalsky M, Reichard K, Inge T, et al. ASMBS pediatric committee best practice guidelines. Surg Obes Relat Dis. Jan-Feb 2012;8(1):1-7. PMID 22030146
145. Pratt JSA, Browne A, Browne NT, et al. ASMBS pediatric metabolic and bariatric surgery guidelines, 2018. Surg Obes Relat Dis. Jul 2018; 14(7): 882-901. PMID 30077361
146. Eisenberg D, Shikora SA, Aarts E, et al. 2022 American Society for Metabolic and Bariatric Surgery (ASMBS) and International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO): Indications for Metabolic and Bariatric Surgery. Surg Obes Relat Dis. Dec 2022; 18(12): 1345-1356. PMID 36280539
147. August GP, Caprio S, Fennoy I, et al. Prevention and treatment of pediatric obesity: an Endocrine Society clinical practice guideline based on expert opinion. J Clin Endocrinol Metab. Dec 2008;93(12):4576-4599. PMID 18782869
148. Styne DM, Arslanian SA, Connor EL, et al. Pediatric Obesity-Assessment, Treatment, and Prevention: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. Mar 01 2017; 102(3): 709-757. PMID 28359099
149. Centers for Medicare and Medicaid Services (CMS). Decision Memo for Bariatric Surgery for the Treatment of Morbid Obesity (CAG-00250R). 2006; https://www.cms.gov/medicare-coverage-database/details/nca-decision-memo.aspx?NCAId = 160. Accessed April 1, 2024.
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Coding Section

Codes	Number	Description
CPT	43290	Esophagogastroduodenoscopy, flexible, transoral; with deployment of intragastric bariatric balloon
	43291	Esophagogastroduodenoscopy, flexible, transoral; with removal of intragastric bariatric balloon(s)
	43332-43337	Repair hiatal hernia surgery code range
	43644	Laparoscopy, surgical, gastric restrictive procedure; with gastric bypass and Roux-en-Y gastroenterostomy (roux limb 150 cm or less) (same procedure as 43846 but performed laparoscopically)
	43645	Laparoscopy, surgical, gastric restrictive procedure; with gastric bypass and small intestine reconstruction to limit absorption (laparoscopic malabsorptive procedure; however, the code does not represent any specific malabsorptive procedure).
	43770	Laparoscopy, surgical, gastric restrictive procedure; placement of adjustable gastric restrictive device (e.g., gastric band and subcutaneous port components) (Adjustable gastric banding)
	43774	Laparoscopy, surgical, gastric restrictive procedure; removal of adjustable gastric restrictive device and subcutaneous port components
	43775	Laparoscopy, surgical, gastric restrictive procedure; longitudinal gastrectomy (i.e., sleeve gastrectomy)
	43842	Gastric restrictive procedure without gastric bypass, for morbid obesity; vertical-banded gastroplasty
	43843	Gastric restrictive procedure, without gastric bypass, for morbid obesity; other than vertical-banded gastroplasty (e.g. plication)
	43845	Gastric restrictive procedure with partial gastrectomy, pylorus-preserving duodenoileostomy and ileoileostomy (50-100 cm common channel) to limit absorption (biliopancreatic diversion with duodenal switch)
	43846	Gastric restrictive procedure, with gastric bypass for morbid obesity; with short limb (150 cm or less) Roux-en-Y gastroenterostomy. (involves both a restrictive and a malabsorptive component, with the horizontal or vertical partition of the stomach performed in association with a Roux-en-Y procedure (i.e., a gastrojejunal). )
	43847	Gastric restrictive procedure, with gastric bypass for morbid obesity; with small intestine reconstruction to limit absorption (Biliopancreatic Diversion; [Scopinaro procedure]; long-limb Roux-en-Y)
	43848	Revision, open, of gastric restrictive procedure for morbid obesity, other than adjustable gastric restrictive device (separate procedure)
	43886-43888	Gastric restrictive procedure, open; removal/replacement of subcutaneous port component code range
HCPCS	C9784	Gastric restrictive procedure, endoscopic sleeve gastroplasty, with esophagogastroduodenoscopy and intraluminal tube insertion, if performed, including all system and tissue anchoring components
	C9785	Endoscopic outlet reduction, gastric pouch application, with endoscopy and intraluminal tube insertion, if performed, including all system and tissue anchoring components
ICD-10-CM	E66.01	Morbid obesity
	E66.2	Morbid obesity with alveolar hypoventilation
	K44.0-K44.9	Diaphragmatic (hiatal) hernia code range
	K91.0-K91.32	Postprocedural complications and disorders of digestive system, code range
	K95.01, K95.09	Complications of gastric band procedure, code range
	K95.81, K95.89	Complications of other bariatric procedure, code range
ICD-10-PCS	0D160ZA, 0D164ZA, 0D168ZA, 0D1607A, 0D160Z9, 0D160ZB, 0D164Z9, 0D164ZB	Surgical, gastrointestinal system, bypass, stomach, code by approach, device, and qualifier
	0DB60ZZ, 0DB63ZZ, 0DB64ZZ, 0DB67ZZ, 0DB68ZZ, 0DB64Z3	Surgical, gastrointestinal system, excision, stomach, code by approach and qualifier
	0DP643Z, 0DP64CZ	Surgical, gastrointestinal system, removal, stomach, open, code by device (extraluminal device or intraluminal device)
	0DQ64ZZ	Surgical, gastrointestinal system, repair, stomach, percutaneous endoscopic approach
	0DV60CZ, 0DV60DZ,0DV60ZZ	Surgical, gastrointestinal system, restriction, stomach, open, code by device (extraluminal device, intraluminal device or no device)
	0DV63CZ, 0DV63DZ,0DV63ZZ	Surgical, gastrointestinal system, restriction, stomach, percutaneous, code by device (extraluminal device, intraluminal device or no device)
	0DV64CZ, 0DV64DZ,0DV64ZZ	Surgical, gastrointestinal system, restriction, stomach, percutaneous endoscopic, code by device (extraluminal device, intraluminal device or no device)
	0DW64CZ	Surgical, gastrointestinal system, revision, stomach, percutaneous endoscopic, extraluminal device
Type of service	Surgery
Place of service	Inpatient

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive.

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community and other nonaffiliated technology evaluation centers, reference to federal regulations, other plan medical policies, and accredited national guidelines.

"Current Procedural Terminology © American Medical Association. All Rights Reserved" 

History From 2014 Forward     

08/12/2024	Adding back to policy the following verbiage that was left off. Revision surgery to address perioperative or late complications of the orginal bariatric procedure may be considered MEDICALLY NECESSARY. They include, but are not limited to, staple-line failure, obstruction, stricture, non-absorption resullting in hypoglycemia or mainutrition, weight loss of 20% or more below ideal body weight, and band slippage that ccannot be corrected with manipulation or adjustment (see Policy Guidelins section). Revision of a primary bariatric procedure that hasfailed due to dilation of the gastric pouch or dilation proximal to an adjustale gastric band (documented by upper gastrointestinal examination or endoscopy) is conidered MEDICALLY NECESSARY if the initial procedure was successful in inducing weight loss prior to pouch dilation, and the patient has been compliant with a prescribed nutrition and exercise program. Converting from one surgical intervention to a second, particularly because the desired weight loss has not been realized, is considered a second procedure and not revision.
08/05/2024	Revision surgery to address perioperative or late complications of the orginal bariatric procedure may be considered MEDICALLY NECESSARY. They include, but are not limited to, staple-line failure, obstruction, stricture, non-absorption resullting in hypoglycemia or mainutrition, weight loss of 20% or more below ideal body weight, and band slippage that ccannot be corrected with manipulation or adjustment (see Policy Guidelins section). Revision of a primary bariatric procedure that hasfailed due to dilation of the gastric pouch or dilation proximal to an adjustale gastric band (documented by upper gastrointestinal examination or endoscopy) is conidered MEDICALLY NECESSARY if the initial procedure was successful in inducing weight loss prior to pouch dilation, and the patient has been compliant with a prescribed nutrition and exercise program. Converting from one surgical intervention to a second, particularly because the desired weight loss has not been realized, is considered a second procedure and not revision.
07/08/2024	Interim review to add policy verbiage regarding TORe procedure and medically refractory GERD. Updating entire policy to include updated obesity classification terminology.
02/05/2024	Corrected date on History box from 01/01/2023 to 01/09/2024. No other change.
01/09/2024	Annual review, adding coverage criteria for individuals with type 2 diabetes and with a BMI >30/kg/m2. Also updating description, guidelines, rationale and references.
02/02/2023	Interim review, no change to policy intent. Updating description, background and rationale.
01/09/2023	Annual review, no change to policy intent. Updating guidelines to remove requirement of 7-10% weight loss during the 4-6 months prior to surgery.
12/14/2022	Annual review, no change to policy intent. Updating rationale and references.
03/30/2022	Interim Review. Updating policy verbiage. Also updating rationale and reference.
12/13/2021	Annual review, no change to policy intent, but, guideline update related to adolescent bariatric surgery made. Also updating rationale and references.
12/02/2020	Annual review, no change to policy intent. Updating rationale and references.
12/16/2019	Annual review, no change to policy intent. UPdating description, regulatory status, guidelines, rationale and references.
01/03/2019	Annual review, no change to policy intent.
01/23/2018	Annual review, rewriting the investigational statement on endoscopic procedures for clarity, also adding aspiration therapy device to the investigational statement. Adding a statement regarding the investigational status of surgical treatment of preadolescent children. Updating background, description, guidelines, regulatory status, rationale and references.
12/01/2016	Annual review, adding Single anastomosis duodenoileal bypass with sleeve gastectomy as investigational. Updating background, description, guidelines, rationale and references.
12/15/2015	Annual review, no change to policy intent.
10/28/2014	Annual review. Laparoscopic gastric plication added as investigational. Statement added related to the repair of incidentally identified hiatal hernias. Changed bariatric surgery on members with BMI < 35 from investigational to not medically necessary. Added coding. Updated background, description, guidelines, rationale and references.
09/11/2014	Added disclaimer note regarding need to review plan document for benefits. No change to policy intent.