New guidelines for weight loss surgery

Two of the top experts in the world on bariatric and metabolic surgery have released new evidence-based clinical guidelines that, among a slew of other recommendations, expand patient eligibility for weight-loss surgery and support metabolic surgery for people with type 2 diabetes starting at a body mass index (BMI) of 30, which is one of several crucial screening criteria for surgery.

The National Institutes of Health (NIH) developed a consensus statement more than 30 years ago that most insurers and physicians still rely on to determine who should have weight-loss surgery, what kind of surgery they should have, and when they should have it. The ASMBS/IFSO Guidelines on Indications for Metabolic and Bariatric Surgery - 2022 are intended to replace this consensus statement.

The International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) represents 72 national associations and societies worldwide, and the American Society for Metabolic and Bariatric Surgery (ASMBS) is the largest organization of bariatric surgeons and integrated health professionals in the United States.

"The 1991 NIH Consensus Statement on Bariatric Surgery served a valuable purpose for a time, but after more than three decades and hundreds of high-quality studies, including randomized clinical trials, it no longer reflects best practices and lacks relevance to today's modern-day procedures and population of patients," said Teresa LaMasters, MD, President, ASMBS. "It's time for a change in thinking and in practice for the sake of patients. It is long overdue."

According to the 1991 consensus statement, only people with a BMI of at least 40 or a BMI of 35 or more and at least one obesity-related condition, such as hypertension or heart disease, were eligible for bariatric surgery. The emerging laparoscopic techniques and procedures that would become standard and make weight-loss surgery as safe as or safer than common operations like gallbladder surgery, appendectomy, and knee replacement were not mentioned, nor were there any references to metabolic surgery for diabetes. Even for those with BMIs over 40, surgery was advised against in the statement because it had not been thoroughly studied.

New Patient Selection Standards -- Times Have Changed

The ASMBS/IFSO Guidelines now recommend metabolic and bariatric surgery for individuals with a BMI of 35 or more "regardless of the presence, absence, or severity of obesity-related conditions" and that it be considered for people with a BMI of 30-34.9 and metabolic disease and in "appropriately selected children and adolescents."

But even without metabolic disease, the guidelines say weight-loss surgery should be considered starting at BMI 30 for people who do not achieve substantial or durable weight loss or obesity disease-related improvement using nonsurgical methods. It was also recommended that obesity definitions using standard BMI thresholds be adjusted by population and that Asian individuals consider weight-loss surgery beginning at a BMI of 27.5.

Higher Levels of Safety and Effectiveness for Modern-Day Weight-Loss Surgery

The new guidelines further state that "metabolic and bariatric surgery is currently the most effective evidence-based treatment for obesity across all BMI classes" and that "studies with long-term follow-up, published in the decades following the 1991 NIH Consensus Statement, have consistently demonstrated that metabolic and bariatric surgery produces superior weight loss outcomes compared with non-operative treatments."

It is also noted that multiple studies have shown significant improvement in metabolic disease and a decrease in overall mortality after surgery and that "older surgical operations have been replaced with safer and more effective operations." Two laparoscopic procedures, sleeve gastrectomy and Roux-en-Y Gastric Bypass (RYGB), now account for about 90% of all operations performed worldwide.

Roughly 1 to 2% of the world's eligible patient population get weight-loss surgery in any given year. Experts say the overly restrictive consensus statement from 1991 has contributed to the limited use of such a proven safe and effective treatment. Globally, more than 650 million adults had obesity in 2016, which is about 13% of the world's adult population. CDC reports over 42% of Americans to have obesity, the highest rate ever in the U.S.

"The ASMBS/IFSO Guidelines provide an important reset when it comes to the treatment of obesity," said Scott Shikora, MD, President, IFSO. "Insurers, policymakers, healthcare providers, and patients should pay close attention and work to remove the barriers and outdated thinking that prevent access to one of the safest, most effective and most studied operations in medicine."