Study finds fewer deaths after bariatric surgery

Deaths following weight loss surgery were lower than reported in previous studies, possibly "because the technology of bariatric surgery and the experience of surgeons have advanced," says Su-Hsin Chang. (Credit: MilitaryHealth/Flickr)

Bariatric surgery is effective at helping people lose weight and is safer than earlier studies have suggested, new research shows.

In addition to weight loss, people who had the surgery saw improvements in related conditions such as diabetes, high blood pressure, and sleep apnea.

“We found that death rates were lower than those reported in previous meta-analyses,” says first author Su-Hsin Chang, an instructor in surgery at Washington University in St. Louis.


“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.”

Outcomes of bariatric surgery have not been systematically evaluated in a large number of trials since 2003. For the new study, published in the Journal of the American Medical Association, researchers looked at 164 randomized clinical trials and observational studies that included, but were not limited to, the three most common bariatric procedures: gastric bypass, adjustable gastric banding, and sleeve gastrectomy.

Across all procedures, the mortality was eight deaths out of 10,000 patients within 30 days of surgery. This mortality increased to 31 deaths out of 10,000 patients after 30 days, based on the data from the randomized clinical trials.

The rate of any type of complication ranged from 10 to 17 percent, with gastric bypass having more complications but also more effective weight loss.

Weight loss surgeries vary

Patients who underwent adjustable gastric banding lost comparatively less weight and were more likely to require another operation to fix problems such as band erosion. Despite requiring more follow-up operations, gastric banding had lower death and complication rates.

Looking at the 11 studies that reported data five years after surgery, the researchers calculated that study participants maintained a 12 to 17 point reduction in body mass index (BMI).

Sleeve gastrectomy appeared comparable to gastric bypass in terms of weight loss and therefore was more effective than adjustable gastric banding.

In addition to the weight loss benefit, the studies showed substantial improvement in conditions associated with obesity. Looking at the studies providing information about diabetes, rates of disease remission—a return to normal blood sugar levels—ranged from 86 to 92 percent. Among the studies reporting blood pressure data, 75 percent of patients returned to normal blood pressure readings following surgery.

The National Cancer Institute at the National Institutes of Health, the Agency for Healthcare Research and Quality, the Foundation for Barnes-Jewish Hospital, and American Cancer Society funded the work.

Source: Washington University in St. Louis