Latest Data Show that Bariatric Surgery Is Effective, and Risks Remain
A review of bariatric surgery studies published between 2003 and 2012—the most recent review of its kind—confirms that bariatric surgery provides “substantial and sustained effects on weight loss and ameliorates obesity-attributable comorbidities in the majority of bariatric patients, although risks of complication, reoperation, and death exist,” said lead author Su-Hsin Chang, PhD, Instructor, Washington University School of Medicine, St Louis, Missouri.
The analyses included 161,756 patients (mean age, 44.5 years) with a mean body mass index (BMI) of 45.62. The findings were published in the March issue of JAMA Surgery.
How Do the Findings Compare With Previous Meta-Analyses?
“Consistent with the findings in previous meta-analyses, we found significant weight reduction and low mortality outcomes associated with surgery,” said Dr. Chang. “However, the estimated mortality rates in our study were lower than those in previous meta-analyses (Buchwald et al and Maggard et al). Possibly, this is because we only included more recent studies published from 2003 to 2012, capturing the fact that the technology of bariatric surgery and the experience of surgeons have advanced,” she said.
“We also found significant improvement in comorbidities, which is consistent with findings in Buchwald et al, while Padwal et al did not find this relationship,” Dr. Chang said. “In accordance with Padwal et al and others, our study found that gastric bypass (GB) is more effective than adjustable gastric banding (AGB) and much more effective than non-surgical intervention in weight loss,” she said.
Clinical Outcomes of Bariatric Surgery
“Mortality after weight loss surgery was low (0.08% for ≤30 days mortality rate and 0.31% for >30 days mortality rate),” Dr. Chang said. “BMI loss at 5-years post-surgery was 12-17 kg/m2. Comorbid conditions were significantly improved after surgery (diabetes was either resolved or improved after surgery in 92% of the patients, 75% for hypertension, 76% for dyslipidemia, and 96% for sleep apnea). The reoperation rate was 7%, and the complication rate was 17%. The rather high complication rate was because the complications in our study was defined as ALL adverse events reported by published studies, including nausea, vomiting, bleeding, reflux, gastrointestinal symptoms, nutritional and electrolyte abnormalities, etc,” Dr. Chang said.
While GB was the most effective type of surgery, it was also associated with the highest rate of complications. AGB had lower mortality and complication rates but a higher reoperation rate, and less weight loss compared with GB. Sleeve gastrectomy (SG) was similar in efficacy to GB and more effective than AGB.
“Regarding safety, as surgeons and hospitals have become more experienced with bariatric surgery, risk has decreased and safety has clearly improved,” commented Jennifer C. Seger, MD, Trustee, American Society of Bariatric Physicians, and Physician, Bariatric Medical Institute of Texas, San Antonio. “However, it is still important to recognize that decreased risk does not equate to ‘no risk,” Dr. Seger said.
“I believe this new information to be quite significant since the AGB often seems more appealing up front as a ‘less risky’, ‘less invasive’, and reversible procedure, however, patients may face more long term risks and complications than originally anticipated, including reoperation,” Dr. Seger said. “This finding, coupled with the fact that AGB is less impactful on improvement of morbidities, calls into question the usefulness of AGB and explains why more surgeons are moving away from performing AGB in lieu of GB and SG,” she noted.
“Perhaps a weakness of this study is … that the follow up in these trials was only 2 years,” Dr. Seger commented.
Dr. Seger added that data from obesity medicine research “is far from complete and greatly biased towards treatment with bariatric surgery. I will leave it to the reader as to why that might be…. I am quite confident that if ‘non-surgical treatment’ [used as a control group in clinical studies] were to include my fellow colleagues, certified by the American Board of Obesity Medicine, the results would be quite different,” she added.