Sleeve gastrectomy vs gastric bypass for weight loss: Which is safer?

Sleeve gastrectomy was associated with a lower risk of mortality and complications over 5 years compared with gastric bypass, although the former intervention comes with an increased risk of surgical revision, reveals a recent study on patients undergoing bariatric surgery for weight loss.

“Understanding the comparative safety of these operations may better inform patients and surgeons in their decision-making,” said the researchers.  

While the two common bariatric procedures have established short-term safety profiles, the comparative safety outcomes between the two remain unclear.

“This limits the ability to answer important questions, such as which bariatric procedure is the safest or which bariatric procedure is best for a given patient,” wrote Drs Anita Courcoulas and Bestoun Ahmed from the University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, US, in a linked commentary. [JAMA Surg 2021;doi:10.1001/jamasurg.2021.4989]

Over a 5-year period after surgery, patients who underwent sleeve gastrectomy had a lower risk of mortality (cumulative incidence, 4.27 percent vs 5.67 percent; adjusted hazard ratio [aHR], 0.84, 95 percent confidence interval [CI], 0.74-0.95) compared with those who had gastric bypass. This, as the authors reported, translates to a number needed to harm of 71. [JAMA Surg 2021;doi:10.1001/jamasurg.2021.4981]

“Had all patients in the current study undergone sleeve gastrectomy, we can estimate that roughly 540 fewer deaths would have occurred at the 5-year time point,” they noted. “This increased risk of mortality may be driven by the increased incidence of complications after gastric bypass.”

In addition, sleeve gastrectomy was also associated with fewer complications (22.10 percent vs 29.03 percent; aHR, 0.73, 95 percent CI, 0.67-0.80) and reinterventions needed (25.23 percent vs 33.57 percent; aHR, 0.77, 95 percent CI, 0.71-0.85) over 5 years compared with gastric bypass.  

While the sleeve gastrectomy cohort was less likely to require hospitalization (aHR, 0.83, 95 percent CI, 0.80-0.86) and visit to emergency department (aHR, 0.87, 95 percent CI, 0.84-0.90) than the gastric bypass group at 1 year after surgery, the differences between the two groups were nullified by 5 years (aHR, 0.99, 95 percent CI, 0.94-1.04 for hospitalization; aHR, 0.97, 95 percent CI, 0.92-1.01 for ED use).

However, patients who underwent sleeve gastrectomy saw increasing risk of surgical revision than the treated with gastric bypass — with aHRs which increased over time from 1.34 at 1 year to 2.53 at 3 years and 3.41 at 5 years (5-year cumulative incidence, 2.91 percent vs 1.46 percent).

“The current study not only provides longer-term outcomes, but demonstrates how trends in outcomes change over time and among important subgroups,” said the researchers. “Although the safety benefits of sleeve gastrectomy over gastric bypass may be generalizable to patients of older age, the risk of revision may not be as significant in this population.”

“It’s really important for patients to understand the risk [vs benefit of] … these two procedures because that helps inform the decision about which type of bariatric surgery to choose,” said lead author Dr Ryan Howard from the University of Michigan in Ann Arbor, Michigan, US.

“You could envision a scenario where a patient is averse to that risk, and so even if a sleeve gastrectomy doesn’t confer as much weight loss, they may want it because it’s the safer surgery,” he explained. “On the other hand, if a patient has a lot of comorbidities, and a bypass is going to afford a better clinical benefit, maybe that risk is worth it.”