Ursodeoxycholic acid in the prevention of gallstone formation after bariatric surgery: a meta-analysis.

BACKGROUND: Rapid weight loss increases risk for gallstone formation. Prophylactic cholecystectomy is difficult. Several small trials have shown that ursodeoxycholic acid (UDCA) may prevent gallstone formation after bariatric surgery. The aim of this study is to assess the efficacy and safety of UDCA in the prevention of gallstone formation after bariatric surgery.

METHODS: Electronic databases, including the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Australasian Medical Index, LILACS, and HERDIN, were searched. Reference lists of trials selected by the above electronic searching were also searched. Authors of the retrieved trials and pharmaceutical companies were also contacted for other trials, published and unpublished. A meta-analysis of all randomized, double-blind, placebo-controlled prospective trials comparing UDCA and placebo was performed.

RESULTS: Five RCTs including 521 patients were assessed. Random effects meta-analysis showed a significant reduction of gallstone formation (RR 0.43, 95% confidence interval 0.22-0.83), with 8.8% of those taking UDCA developing gallstones compared to 27.7% for placebo. Although this meta-analysis is heterogeneous with I(2) of 61.9%, the directions of the effect are all consistently in favor of UDCA (p=0.01). A meta-analysis on the adverse effects could not be performed because the studies did not report them in a way to make the analysis possible.

CONCLUSIONS: UDCA can prevent gallstone formation after bariatric surgery.