Treatment of choledocholithiasis with oral chenodeoxycholic acid.

The aim of this study was to conduct a controlled trial of oral chenodeoxycholic acid in the management of radiolucent choledocholithiasis. Thirteen patients were randomized in double-blind fashion to receive either 750 mg/day of chenodeoxycholic acid (CDCA) or a placebo. After 4 months, those who had the placebo were administered CDCA; those who had received CDCA and showed a 25% or more decrease in the size of stones (evaluated blindly) received CDCA for an additional 4 months. Five of the 13 patients did not complete the study; four (one initially placebo and three CDCA) because acute biliary symptoms mandated operative intervention and one (initially placebo, then CDCA) because of asymptomatic elevations of the serum transaminase levels. Patients who were withdrawn from the study had significantly larger stones (P less than 0.02) (mean largest diameter, 11.4 mm +/- 1.6 SEM) than those who completed the study (6.5 +/- 0.5). Of the eight patients who completed the study, two of the three who received CDCA initially for 6 to 8 months experienced complete disappearance of stones; all five patients who took the placebo failed to show dissolution, and one of these subsequently had dissolution of stones after 8 months of CDCA. Biliary lipid analyses during treatment showed bile unsaturated with respect to cholesterol in the three patients whose stones dissolved with CDCA therapy. In conclusion, a patient with partial dissolution of stones and unsaturated bile after 4 months of CDCA probably will have complete dissolution of stones after 6 to 8 months of CDCA.