Newswise — BOSTON – Nov. 6, 2014 – Laparoscopic gastric bypass surgery in patients with type 2 diabetes, once considered a high-risk procedure, carries a complication and mortality rate comparable to some of the safest and most commonly performed surgeries in America, including gallbladder surgery, appendectomy, and total knee replacement, according to new research from the Cleveland Clinic Bariatric and Metabolic Institute.

Findings from the new study, “How Safe is Metabolic/Diabetes Surgery?”,* were presented here at the 31st Annual Meeting of the American Society for Metabolic and Bariatric Surgery (ASMBS) during ObesityWeek 2014, the largest international event focused on the basic science, clinical application and prevention and treatment of obesity. ObesityWeek 2014 is hosted by the ASMBS and The Obesity Society (TOS).

The 30-day complication rate associated with metabolic surgery, specifically gastric bypass, was 3.4 percent, about the same rate as laparoscopic cholecystectomy (gallbladder surgery) and hysterectomy. Hospital stays and readmission rates were similar to laparoscopic appendectomy. The month-long mortality rate for metabolic or diabetes surgery was 0.30 percent, about that of total knee replacement, and about one-tenth the risk of death after cardiovascular surgery. Gastric bypass patients had significantly better short-term outcomes in all examined variables compared to laparoscopic colon resections.

“The perception has been that gastric bypass is a very risky operation, but the reality is, it is as safe, if not safer, than many of the most commonly performed surgeries in America,” said study co-author Ali Aminian, MD, Clinical Scholar of Advanced Metabolic and Diabetes Surgery at Cleveland Clinic. “The risk-to-benefit ratio of gastric bypass for diabetes and obesity is very favorable. There’s significant weight loss, diabetes improvement or remission, and a relatively low complication and mortality rate. In addition, earlier intervention with metabolic surgery may eliminate the need for some later higher-risk procedures to treat cardiovascular complications of diabetes.”

Researchers reviewed a national database** of 66,678 patients with diabetes who had various surgical procedures including laparoscopic gallbladder surgery, appendectomy, partial colon resections, hysterectomy, heart surgery and total knee replacement between 2007 and 2012. The complication and mortality rates of these procedures were compared to those of the 16,509 patients in the group who had laparoscopic gastric bypass.

Doctors have discovered that gastric bypass procedures can have a nearly immediate effect on patients with type 2 diabetes – in a matter of hours or days, long before weight loss occurs. Sometimes patients walk out of the hospital without medications. Another Cleveland Clinic study published this year in The New England Journal of Medicine found diabetes remission rates three years after bariatric surgery were 35 percent, compared to zero for patients treated with pharmacotherapy. \

Gastric bypass surgery reduces the size of the stomach and allows food to bypass part of the small intestine, reducing the amount of food patients can eat at one time and limiting the absorption of food.

“This study demonstrates that surgical treatment of obesity and diabetes is as safe as other commonly performed surgical procedures. This study, along with many others, can help patients with diabetes and their doctors make better informed and realistic decisions about the potential risks and clear benefits of metabolic surgery,” said John M. Morton, Chief, Bariatric and Minimally Invasive Surgery, Stanford University School of Medicine, who was not involved in the study. “Metabolic surgery is a safe and effective treatment, and the data shows, it’s only getting safer.”

The study authors say the database used only includes short-term postoperative outcomes and that that more studies on the long-term effects of surgery are needed.

In addition to Dr. Aminian, study authors include Stacy A. Brethauer, MD; John P. Kirwan, PhD; Sangeeta Kashyap, MD; Bartolome Burguera; and Philip R. Schauer, MD, all from Cleveland Clinic.

About Obesity and Metabolic and Bariatric SurgeryAccording to the Centers of Disease Control and Prevention (CDC), more than 78 million adults were obese in 2011–2012.1 The ASMBS estimates about 24 million people have severe obesity. Individuals with a BMI greater than 30 have a 50 to 100 percent increased risk of premature death compared to healthy weight individuals as well as an increased risk of developing more than 40 obesity-related diseases and conditions including type 2 diabetes, heart disease and cancer.2,3

Metabolic/bariatric surgery has been shown to be the most effective and long lasting treatment for severe obesity and many related conditions and results in significant weight loss. The Agency for Healthcare Research and Quality (AHRQ) reported significant improvements in the safety of metabolic/bariatric surgery due in large part to improved laparoscopic techniques.4 The risk of death is about 0.1 percent5 and the overall likelihood of major complications is about 4 percent.6

About the ASMBS The ASMBS is the largest organization for bariatric surgeons in the nation. It is a non-profit organization that works to advance the art and science of bariatric surgery and is committed to educating medical professionals and the lay public about bariatric surgery as an option for the treatment of severe obesity, as well as the associated risks and benefits. It encourages its members to investigate and discover new advances in bariatric surgery, while maintaining a steady exchange of experiences and ideas that may lead to improved surgical outcomes for patients with severe obesity. For more information, visit


*Does Taste Perception Change After Bariatric Surgery? -- John M. Morton, MD; Ulysses. S. Rosas, BA; Daniel Rogan, BS; Michelle Moore; Stanford University School of Medicine, Presented November 4, 2014

-----------------------------------------1Prevalence of Obesity Among Adults: United States, 2011–2012. (2013). Center for Disease Control and Prevention. Access October 2013 from 2Office of the Surgeon General – U.S. Department of Health and Human Services. (2004). Overweight and obesity: health consequences. Accessed October 2013 from 3Kaplan, L. M. (2003). Body weight regulation and obesity. Journal of Gastrointestinal Surgery. 7(4) pp. 443-51. Doi:10.1016/S1091-255X(03)00047-7. Accessed October 2013.4Encinosa, W. E., et al. (2009). Recent improvements in bariatric surgery outcomes. Medical Care. 47(5) pp. 531-535. Accessed October 2013 from 5Agency for Healthcare Research and Quality (AHRQ). (2007). Statistical Brief #23. Bariatric Surgery Utilization and Outcomes in 1998 and 2004. Accessed October 2013 from 6Flum, D. R., et al. (2009). Perioperative safety in the longitudinal assessment of bariatric surgery. New England Journal of Medicine. 361 pp.445-454. Accessed October 2013 from

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31st Annual Meeting of the American Society for Metabolic and Bariatric Surgery