Clinical Study on Causative Factors and Recurrence of Choledocholithiasis

To identify factors involved in choledocholithiasis, clinical characteristics were studied using univariate and multivariate analyses. Factors involved in recurrence were also investigated. The subjects consisted of 51 patients with calcium bilirubinate stones (B group) and 52 patients with cholesterol stones (C group). All patients had choledocholithiasis and underwent lithotripsy by endoscopic sphincterotomy (EST) during the past 9 years. Twenty variables, including clinical symptoms and endoscopic retrograde cholangiopancreatography (ERCP) findings, were analyzed using a Statistical Analysis System (SAS) software package. Univariate analysis were done using Student's t-test and the chi-square test. Multivariate analyses were done by stepwise logistic regression analysis. In univariate analyses, there were significant differences between the B group and C group in nine variables: age, common bile duct diameter, common hepatic duct diameter, common bile duct stone diameter, cystic duct diameter, and the presence of gallbladder stones, atypical arrangement of the hepatic duct, parapapillary diverticulum, and large parapapillary diverticulum. In multivariate analysis, the four variables of no gallbladder stone, large parapapillary diverticulum, cystic duct less than 8 mm, and atypical arrangement of the hepatic duct were significant independent factors for the development of stones in the B group, with relative risks of 37.75, 16.73, 5.56, and 5.49, respectively. The results indicated that calcium bilirubinate stones were frequently associated with parapapillary diverticulum and abnormal arrangement of the bile duct. The formation of these stones was attributed to chronic biliary stasis caused by dysfunction of the biliary tract, including the papilla. In contrast, most cholesterol stones found in the common bile duct had apparently descended from the gallbladder. Common bile duct stones recurred after EST in 9 patients, all of whom had calcium bilirubinate stones. On ERCP, recurrence was found to be frequently associated with gallbladder stones, large parapapillary diverticula, and atypical arrangement of the hepatic duct. Patients with these characteristics on initial ERCP should therefore receive appropriate treatment and undergo strict follow-up observations owing to the increased risk of recurrence caused by dysfunction of the biliary tract.