Clinical Significance and Long-Term Outcome of Incidentally Found Bile Duct Dilatation

The significance of incidentally detected bile duct dilatation has not yet been elucidated and there are only a few studies on asymptomatic patients with a dilated bile duct. This study aimed to investigate the causes and natural course of bile duct dilatation in asymptomatic patients. A retrospective review of medical records was conducted for individuals in whom bile duct dilatation was detected by routine screening abdominal ultrasound at a health promotion center in Samsung Medical Center from January 2005 to April 2008. A total of 514 patients were included; the mean age was 60.1 +/- A 9.9 and the median follow-up period was 72 (interquartile range 56-85) months. Thirty-eight individuals who had a definite cause or biliary disease requiring treatment at the time of detection of bile duct dilatation were compared with 476 individuals who did not have a definitive cause or who did not need treatment. Both common bile duct (CBD) dilatation and intrahepatic bile duct (IHBD) dilatation were significantly related to the presence of a definitive causative lesion (OR 3.95; 95 % CI 1.77-8.82; p = 0.001). In the IHBD dilatation group, the severity of dilatation was also associated with the presence of a definitive causative lesion (OR 5.77; 95 % CI 1.32-25.26; p = 0.020). Incidentally found biliary dilatation could be a prodrome of significant biliary tree disease. Therefore, further evaluation and regular follow up should be considered especially for marked IHBD dilatation or concomitant dilatation of CBD and IHBD detected on ultrasound.