EUS-guided biliary drainage (BD) is highly effective in patients with distal malignant biliary obstruction (DMBO). However, the concomitant presence of duodenal invasion (DI) may negatively affect the outcome of EUS-BD. We aimed to investigate the effect of duodenal invasion on the outcomes of EUS-BD.

This retrospective single-center study included patients who underwent EUS-BD for DMBO at our institution from August 2023 to October 2025. EUS-BD outcomes, the presence of DI, as well as associated symptoms and treatments performed were evaluated. Categorical variables were compared using the chi-square test.

During the study period, 38 patients underwent EUS-BD for DMBO (18 males, 57.9%; median age 73, range 50-96; 15 choledochoduodenostomies, 13 gallbladder drainages, 10 hepaticogastrostomies). In 21/38 (55.3%) a coaxial double pigtail plastic stent was placed. Twenty-six patients (26/38; 68.4%) presented endoscopic signs of DI. Among these, 14/26 (53.8%) were treated for gastric outlet obstruction symptoms (9 EUS-guided gastroenterostomies, 5 duodenal SEMS). The technical and clinical success rates of EUS-BD were 38/38 (100%) and 36/38 (94.7%), respectively. Six patients (6/36, 16.7%; 3 choledochoduodenostomies; 3 gallbladder drainages) experienced EUS-BD dysfunction after a median of 63 days (range 21–90). Despite a trend indicating an increased risk of dysfunction in presence of DI, no significant differences were found between patients with and without DI (6/26, 23.1% vs 0/12, 0%, p=0.15). However, patients with asymptomatic DI had a significantly higher dysfunction rate compared to symptomatic treated patients (5/12, 41.7% vs 1/14, 7.1%; p = 0.037). 

Asymptomatic DI is associated with a higher risk of EUS-BD dysfunction. If confirmed in larger cohorts, these findings suggest that specific management strategies may be needed for these patients to improve EUS-BD outcomes.