Selection methods for endoscopic ultrasound‑guided biliary drainage cases that are appropriate for beginners

Endoscopic ultrasound-guided biliary drainage (EUS-BD) is performed as a second drainage method when endoscopic retrograde cholangiopancreatography-guided biliary drainage fails. There are several severe adverse events in EUS-BD, and avoiding technical failure is desirable. Although EUS-BD is a skilled endoscopic treatment, the appropriate conditions for EUS-BD beginners are not well known. The present study aimed to clarify the appropriate cases for EUS-BD beginners. The present retrospective cohort study included patients with malignant biliary obstruction who underwent EUS-BD, which was performed by beginners between March 2005 and June 2024. Factors associated with successful EUS-BD performed by beginners were evaluated by multivariate logistic regression analysis. The performance of each factor was evaluated via a receiver operating characteristic (ROC) curve. According to multivariate analysis, the diameter of the punctured bile duct was associated with successful EUS-BD performed by beginners (odds ratio, 1.34; 95% CI, 1.03-1.75; P=0.031). The area under the ROC curve for the diameter of the punctured bile duct was 0.79, and the cutoff value was 6.7 mm (71% sensitivity and 81.8% specificity). The diameter of the punctured bile duct might be associated with successful EUS-BD procedures performed by beginners. When a beginner performs EUS-BD, a diameter of the targeted bile duct >6.7 mm might be desirable for successful procedures.