Investigation of factors related to successful puncture of the intrahepatic bile duct in endoscopic ultrasound-guided biliary drainage

Background The factors associated with the success of each step of EUS-BD have not been fully explored. This study aimed to identify the factors associated with successful bile duct puncture for EUS-BD.Methods We retrospectively reviewed the data of patients with malignant biliary obstruction who underwent EUS-BD at a single institution between 2015 and 2025.Results EUS-BD was used to perform 46 bile duct punctures on 33 patients. The success rate of bile duct puncture was 80.4%. According to multivariate analysis, the angle of the scope and the puncture needle on the EUS monitor was identified as factors associated with the success of bile duct puncture (p < 0.01). The cutoff value for the angle between the scope and the puncture needle was 59 degrees, the area under the curve (AUC) was 0.86, the sensitivity of 75.7%, and the specificity was 100%.Conclusions The angle of the scope and the puncture needle was identified as factors associated with the success of bile duct puncture. Applying a strong up-angle to the scope and minimizing the use of the elevator to adjust the angle between the scope and the puncture needle may improve the success rate of bile duct puncture during EUS-BD.