Risk of death following bariatric surgery

Oct 16 2007

Approximately 1 percent of Pennsylvania residents who underwent bariatric surgery between 1995 and 2004 died within one year of the surgery and nearly 6 percent died within five years, according to a report in the October issue of Archives of Surgery, a theme issue on bariatric surgery.

Death rates overall, as well as deaths from heart disease and suicide, were higher than those of the general state population.

Bariatric surgery has emerged as an effective treatment for severe obesity, according to background information in the article. Obese individuals typically lose up to 80 percent of their excess body weight one to two years after the operation. “Bariatric surgery results in clinical improvement and resolution of the obesity-related comorbid diseases,” the authors write, including diabetes, high blood pressure and high cholesterol.

Bennet I. Omalu, M.D., M.P.H., of the University of Pittsburgh, and colleagues analyzed data on all bariatric operations performed on Pennsylvania residents between 1995 and 2004. Following 16,683 operations, 440 patients (2.6 percent) died.

“Age- and sex-specific death rates after bariatric surgery were substantially higher than comparable rates for the age- and sex-matched Pennsylvania population,” the authors write. “This continued high mortality rate is likely a function of the initial comorbidities related to substantial obesity and the likelihood that the patients remain obese even after the substantial weight loss and have remaining comorbidities.”

The researchers found that:

• Less than 1 percent of the deaths occurred within the first 30 days after surgery.

• The one-year case fatality rate was approximately 1 percent and at 5 years, the cumulative case fatality was 6.4 percent.

• Death rates increased with age, especially among patients older than 65; the average age at surgery was 48 years.

• Heart disease was the leading cause of death, cited for 76 patients (19.2 percent). Rates of death from heart disease were higher among bariatric surgery patients than the general population.

• Of 45 deaths from traumatic causes, 16 (4 percent of all deaths) were suicides and 14 (3 percent) were drug overdoses not classified as suicides. Based on national statistics for the general population, only two suicide deaths would have been expected among this number of individuals.

“It is likely that this continued excess mortality after bariatric surgery could be reduced by better coordination of follow-up after the surgery, especially control of high risk factors such as hypertension, diabetes mellitus, hyperlipidemia [high cholesterol] and smoking, as well as efforts to prevent weight regain by diet and exercise and psychological support to prevent and treat depression and suicide,” the authors conclude.

http://archsurg.ama-assn.org/