New Guidelines for Bariatric Surgery

New Guidelines for Bariatric Surgery

November 30, 2022

November 2022 Letter from the Director

This month's newsletter is written by guest author Shanu N. Kothari, MD, FACS, FASMBS. He is the Jean and H. Harlan Stone Chair of Surgery at Prisma Health in Greenville, SC. He is also Professor of Surgery at the University of South Carolina – Greenville. He is the immediate past president of the American Society for Metabolic and Bariatric Surgery.

The year 1991 was a significant year in our country’s history. Herbert Walker Bush was President of the United States. The number one movie in the United States was Silence of the Lambs. The internet became commercially available. Mikhail Gorbachev resigned as president of the Soviet Union. It was also the year that the National Institutes of Health (NIH) published their consensus guidelines for indications for bariatric surgery.

The NIH guidelines stated that surgery was indicated for patients with the BMI of 40 or greater or 35 to 39.9 with significant comorbidities after multiple failed dietary attempts. In the past 31 years, not only has our country undergone significant changes, our understanding of the disease of obesity along with safety, reliability, and reproducibility of our various interventions has changed as well. We now have six American Society of Metabolic and Bariatric Surgery (ASMBS) endorsed surgical procedures. We have a wealth of literature touting the benefits of minimally invasive procedures over our traditional open techniques, specifically around decreased wound related morbidity, incisional hernias, and decreased length of stay, all of which have transformed the care of our patients. Now, we have multiple prospective randomized trials on a variety of surgical procedures showing the superiority of metabolic and bariatric surgical intervention to maximal medical therapy for not only weight loss but Type 2 diabetes as well. Consequently, an update to the NIH Consensus Conference from 1991 is long overdue.

In addition, the National Institutes of Health is no longer in the business of creating consensus guidelines and as a result, we are trapped in the past. ASMBS took this opportunity, working with the International Federation for the Society of Obesity (IFSO), to update these guidelines. I am happy to report that this collaborative international effort has resulted in open access to the guidelines through both of our leading journals, Surgery for Obesity And Related Disease (SOARD) as well as Obesity Surgery.

Based on the new guidelines, metabolic and bariatric surgery (MBS) is recommended for individuals:

  • with a BMI greater than 35 kg / m² regardless of presence, absence, or severity of comorbid conditions,

  •  with type 2 diabetes with a BMI greater than 35 kg / m², and

  • should be considered in individuals with a BMI of 30 – 34.9 kg / m² who cannot achieve substantial or durable weight loss or comorbidity improvement using nonsurgical methods.

In addition, our current BMI thresholds for obesity discriminate against those of Asian ethnicity where comorbid conditions such as type 2 diabetes and high blood pressure impact the Asian population at a lower BMI. Based on these data, we have lowered the BMI threshold to 27.5 for consideration of metabolic surgical intervention in patients of Asian ethnicity.

Other changes include no upper age limit to MBS. This is a risk benefit analysis that should be completed on an individual basis with input from a multidisciplinary team and is the surgeon making the decision in a shared decision-making approach with the patient. We know that chronological age in and of itself is not a contraindication and that frailty index would be a better marker of risk in this population. In addition, children and adolescents with a BMI greater than 120% of the 95 percentile and a major comorbidity or BMI greater than 140% of the 95 percentile should be considered for MBS after evaluation by a multidisciplinary team in a specialized center. The updated guidelines also recommend MBS as a bridge to other surgical specialty interventions including joint arthroplasty, abdominal wall hernia repair, and organ transplantation. Finally, like many other diseases, obesity is a chronic disease requiring lifelong management after any intervention including primary metabolic surgery. This may include revisional surgery or other therapies including endoscopic and pharmaceutical interventions to achieve a desired treatment effect.

Now that we have armed our membership of our respective societies with these updated guidelines and have the endorsement of over 72 countries, it is time to take this message to the payors. We have already begun to see anecdotal wins on peer-to-peer reviews, getting denials overturned based on our new 2022 guidelines. The next steps are to go to the various payors and to get their indications for metabolic surgery to match the 2022 guidelines and to abolish the 1991 guidelines. Ultimately, our goal will also be to get CMS to endorse these updated evidence-based indications for metabolic and bariatric surgery.

Finally, we must stop referencing the 1991 guidelines in all our publications and use the 2022 guidelines moving forward for all publications. This will truly take a grass roots effort from everyone who is involved in the treatment of obesity for us to see the worldwide adoption of the 2022 ASMBS/IFSO Indications for metabolic and bariatric surgery.


  Shanu N. Kothari, MD, FACS, FASMBS
  The Jean and H. Harlan Stone Chair of Surgery

  Professor of Surgery, USC School of Medicine Greenville
  President Elect, The Fellowship Council
                        Immediate Past President, ASMBS
                        [email protected]

Read more at: