Medical treatment of biliary duct stones: effect of ursodeoxycholic acid administration

Twenty-eight patients with radiolucent biliary duct stones without cholangitis and jaundice were randomly allocated into two treatment groups receiving ursodeoxycholic acid 12 mg/kg (group A) or placebo (group B) in three daily doses for 24 months. In group A stones disappeared completely in seven patients and partially in one; placebo administration had no effect on stone size and three patients of group B (only one of group A) went to surgery for complications. Ursodeoxycholic acid treatment did not adversely affect liver function tests, and alkaline phosphatase decreased. Abdominal and biliary colics also became less frequent in the first six months of therapy in group A, but not in the placebo group. The bile was supersaturated with cholesterol in both groups, but decreased significantly only in patients receiving ursodeoxycholic acid even though the lithogenic index remained high. Cholesterol saturation of bile does not seem to be the only factor determining the dissolution of biliary duct stones which sometimes contain cholesterol as the main component.