Prevalence and Clinical Outcomes of Common Bile Duct Dilation in Patients Who Use Opium.

Background: This study aimed to evaluate the association of various opium-related factors with common bile duct (CBD) diameter in individuals who use opium in the general population and investigate the clinical importance and long-term outcomes.

Materials And Methods: In this prospective study, 2,400 participants were randomly selected from the Golestan Cohort study. Opium consumption data were recorded. CBD diameter was measured by ultrasound. Transient elastography was performed at enrollment and 3 years later. Participants were followed up for at least 5 years.

Results: A total of 1,599 individuals, aged above 50 years, were enrolled and 167 subjects were users of opium. CBD diameter was significantly higher in users of opium than controls (mean ± standard deviation:5.54 ± 1.95 versus 4.74 ± 1.34mm, P < 0.001). This difference was noted with all opium types, but mostly by users of heroin (P < 0.001). Ingestion of opium caused greater CBD dilatation than inhalation (coefficient: 1.16; 95% CI: 0.05-2.27, P = 0.04 versus coefficient: 0.98; 95% CI: 0.75-1.20, P < 0.001). Transient elastography results did not show any association between fibroscan score change and CBD diameter. No major related malignancy was seen during follow-up.

Conclusions: This study strengthened the evidence of an association of opium use with increased CBD diameter in a population-based setting without significantly increased risk of pancreaticobiliary malignancies or liver fibrosis. We cautiously suggest that opium-induced CBD dilatation may not require further diagnostic work-up.