Risk of Late Adverse Events 'Non-Negligible' With Bariatric Surgery

By Anne Harding

August 22, 2019

NEW YORK (Reuters Health) - Bariatric surgery reduces long-term mortality in obese patients, but also carries a "significantly high" risk of late adverse events, according to new research.

"Even if long-term benefits of bariatric surgery have been demonstrated (including lower long-term mortality compared to control group, as we found in this current study), this surgery is associated with a non-negligible rate of long-term adverse events (including GI surgery and nutritional deficiencies)," said Dr. Jeremie Thereaux of Caisse Nationale d’Assurance Maladie in Paris.

"However, concerns about long-term psychiatric complications (as found in previous studies) have not been confirmed in our study," he told Reuters Health by email.

In their report, online August 2 in The Lancet Diabetes and Endocrinology, Dr. Thereaux and colleagues reviewed French National Health Insurance data for nearly 9,000 patients who underwent gastric bypass or sleeve gastrectomy in 2009. Follow-up lasted a mean 6.8 years.

Mortality was significantly lower for gastric bypass and sleeve-gastrectomy patients compared to obese controls who did not undergo bariatric surgery (hazard ratios, 0.64 and 0.38, respectively).

However, bariatric surgery patients were at significantly increased risk of complications including invasive gastrointestinal (GI) surgery or endoscopy (incidence rate ratio, 2.4 with gastric bypass and 1.5 with sleeve gastrectomy); GI disorders not requiring invasive treatment (IRR, 1.9 and 1.2, respectively); and nutritional disorders (IRR, 4.9 and 1.8).

Neither procedure was significantly associated with any psychiatric disorder, aside from gastric bypass with alcohol dependence (IRR, 1.8).

Gallstone disorders were the most common adverse events.

U.S. and European guidelines have "clearly underlined" the importance of systematic supplementation after bariatric surgery, Dr. Thereaux notes, and following these guidelines would reduce the risk of nutritional disorders.

"However, as we previously published, the main critical issue about BS is the difficulty to organize and perform an efficient long-term follow-up," he said.

"Despite previous alarming studies about psychiatric risks (especially suicide attempt), our study does not confirm them, except for gastric bypass and alcohol dependence," he added.

"The mentioned lack of detailed information regarding patient follow-up highlights the need for establishing a consensus European or worldwide register that ensures careful and robust data collection, improves public reporting, eliminates losses to follow-up, and fosters transparency about bariatric surgery outcomes," Dr. Xabier Unamuno of the University of Navarra in Pamplona, Spain, and colleagues write in an accompanying comment.

"Moreover, to develop more effective bariatric interventions and improve surgical treatments, novel patient-centred approaches that might focus on subsets of specific populations to avoid long-term adverse effects and mitigate potential unintended consequences are required," they conclude.

The study had no external funding.

SOURCE: https://bit.ly/2NjvDVF and https://bit.ly/2ZjAigC

Lancet Diabetes Endocrinol 2019.