Epidemiology, Prognosis, and Treatment Effectiveness of Asymptomatic Biliary Dilatation

Biliary dilation (BD) is a common and complex benign biliary disorder, for which surgical resection remains the only definitive treatment. However, while there are numerous studies on symptomatic BD, there is a lack of systematic, reliable data that describing the population structure, complication rates, comparing natural history and postoperative outcomes of patients whom incidentally detected by imaging and have no biliary symptoms. This multicenter, ambidirectional cohort study aims to consecutively recruit asymptomatic BD patients from 25 tertiary medical centers across China and to systematically collect their clinicopathological data-including demographic characteristics, baseline clinical features, laboratory and imaging results, biliary specific biomarkers, and longitudinal follow up records-in order to establish an asymptomatic subcohort within the larger China BD cohort. Based on this subcohort, the research objectives are structured as follows:

1. Database Establishment and Maintenance: Construct and continuously update a multicenter clinical database for asymptomatic BD patients in China, ensuring data completeness and accessibility.
2. Epidemiological Characterization of Asymptomatic BD: Describe the epidemiological features of asymptomatic BD patients, including demographic profiles (age, sex), distribution of Todani classifications, incidence of various complications, and risk of malignant transformation.
3. Comparison of Surgical Treatment Versus Conservative Observation: Compare key clinical outcomes between asymptomatic BD patients who undergo surgical intervention and those managed by medical observation, thereby providing evidence-based guidance for clinical decision making in this population.