NEW YORK (Reuters Health) – In general, bariatric surgery is associated with a low risk of death and other adverse events in the 30-day postoperative period, according to study findings in The New England Journal of Medicine for July 30.

However, the results indicate that the exact risk of complications varies considerably by patient characteristics. In particular, patients with a history of deep-vein thrombosis or pulmonary embolus, obstructive sleep apnea, or an impaired function status were at increased risk for adverse events. Also, subjects with a body mass index of 75 or higher were elevated risk for complications.

In the new study, Dr. David R. Flum, from the University of Washington, Seattle, and colleagues from the Longitudinal Assessment of Bariatric Surgery Consortium assessed the 30-day outcomes of 4776 patients who underwent a first-time bariatric operation at 1 of 10 cites in the US from 2005 to 2007.

The main outcome measure was a composite of major adverse outcomes, including death, venous thromboembolism, reintervention, and failure to be discharged from the hospital.

The median body mass index was 46.5. Over half of the patients had two or more coexisting medical conditions, the authors report.

Roux-en-Y gastric bypass was the most common operation, performed in 3412 patients and done laparoscopically in 87.2% of cases. Of the remaining patients, 1198 underwent laparoscopic adjustable gastric banding and 166 underwent other operations and were excluded from the analysis.

Overall, 4.3% of patients had at least one major adverse outcome within 30 days of surgery. The death rate was 0.3%.

While a number of factors were linked to perioperative complications, there were also many that had no bearing on risk, including age, gender, race, ethnicity, and other coexisting conditions.

“One must treat obesity aggressively, though thoughtfully, and with an eye toward developing effective prevention and better therapies that ideally would eliminate the need for surgery altogether,” Dr. Malcolm K. Robinson, from Harvard Medical School, Boston, comments in a related editorial. “But until we get to that point, the weight of the evidence indicates that bariatric surgery is safe, effective, and affordable.”

Reference:
N Engl J Med 2009;361:445-454,520-521.