BARIATRIC surgery is a safe and long-term treatment for weight loss; however, the rapid weight loss it induces is a major risk factor for the formation of cholesterol gallstones. The causal link between weight-loss and gallstone formation is not fully understood, but an important factor is the consequential imbalance in biliary lipids. Cholecystectomy at the time of bariatric surgery is the current standard treatment for gallstones, the evidence for the use of ursodeoxycholic acid (UDCA) prophylaxis is still under debate. Research led by Sylke Haal, Amsterdam UMC, University of Amsterdam, the Netherlands, was conducted to provide evidence for whether UDCA reduces the occurrence of gallstone disease after bariatric surgery.
In this multicentre, double-blind, randomised, placebo-controlled, superiority trial, patients underwent a gallbladder ultrasound to determine the presence of asymptomatic gallstones. At study commencement, 985 patients were enrolled and randomly assigned to treatment with 900 mg of UCDA daily for 6 months or placebo. Primary endpoint was determined using a chi-squared test to quantify a significant difference between the two trial arms paired with a logistic regression to test for interactions between the subgroups.
After exclusion criteria were examined, 959 patients were included for analysis and 20% were found to have asymptomatic gallstones at baseline testing. The primary endpoint, symptomatic gallbladder disease, was found in 6.5% of the treatment group compared with 9.7% of the placebo arm. This equated to a relative risk of 0.67, which at 95% confidence interval was not statistically significant. The logistic regression analysis demonstrated a significant interaction between UDCA and the presence of asymptomatic gallstones at baseline. A beneficial impact from UDCA was observed in patients without gallstones at baseline. No significant safety concerns were noted throughout the trial.
The results from the trial suggested that in bariatric surgery patients with no gallstones prior to surgery, UDCA prophylactic treatment for 6 months led to a clinically relevant and significant reduction of symptomatic gallstone disease relative to the placebo.
