The clinical significance of common bile-duct dilatation in patients without biliary symptoms or causative lesions on ultrasonography

Background and Study Aims: Although abdominal ultrasonography (US) is a goo d initial screening method for detection of biliary tract disease, we somet imes encounter patients who only have findings of dilatation of the common bile duct (CBD) on US, without specific biliary symptoms or jaundice. This study aimed to evaluate the causes and clinical significance of dilatation of the CBD in patients without biliary symptoms, jaundice, or causative les ions at US. Patients and Methods: A total of 77 patients who had no biliary symptoms an d whose internal CBD diameter was more than 7 mm, without definite causativ e lesions on US, were enrolled. Of these, 49 underwent endoscopic retrograd e cholangiopancreatography (ERCP) and 28 underwent follow-up US or computed tomography (CT) instead of ERCP. We excluded patients whose bilirubin leve l had increased beyond the upper normal level or who had previous history o f upper abdominal surgery including cholecystectomy. Results: The ERCP findings were as follows: no lesion in 20 patients (40.8% ), juxtapapillary duodenal diverticulum (JDD) in 11 (22.5%), benign strictu re in ten (20.4%), distal CBD mass in two (4.1%), choledochal cyst in two ( 4.1%), anomalous union of the pancreaticobiliary duct (AUPBD) in two (4.1%) , and choledochal cyst with AUPBD in two (4.1%). There were no differences in age or in alkaline phosphatase or gamma-glutamyl transpeptidase (GGT) le vels between the patients who had causative lesions revealed at ERCP and th ose who did not. Among the 28 patients who did not undergo ERCP, 12 had ret urned to normal and eight had no change in CBD diameter on follow-up US. Am ong eight patients who underwent CT, there were four with normal findings, one with JDD, and three with suspected choledochal cysts. Conclusions: We detected a significant number of causative biliary tract le sions in asymptomatic adults with dilatation of the CBD on routine abdomina l US; no laboratory or demographic parameters were useful for discriminatio n. Further diagnostic study will be helpful for the early diagnosis of bili ary tract disease in such patients.