Advanced cannulation techniques vs early EUS-BD in case of difficult biliary cannulation in patients with DMBO: an international propensity score-matched analysis

BACKGROUND AND OBJECTIVES: Biliary drainage(BD)in distal malignant biliary obstruction(DMBO)is often hampered by difficult biliary cannulation(DBC)during endoscopic retrograde cholangiopancreatography(ERCP). Advanced cannulation techniques(aERCP)may overcome DBC but still fail in up to 15% of cases, increasing the risk of adverse events(AEs). Early endoscopic ultrasound-guided BD(eEUS-BD)is a potential alternative. The aim of this study is to directly compare safety and efficacy of EUS-BD and aERCP. METHODS: This is a retrospective, multicentric study(29 centres in United States, Canada, Europe), including patients with DMBO and common bile duct(CBD)diameter >12 mm, treated up to 2024. DBC cases managed with either eEUS-BD or aERCP were analysed. A 1:2 propensity score-matched cohort was generated to ensure comparability, with regression modeling and inverse probability of treatment weighting(IPTW)performed as sensitivity analyses. AEs rate was the primary outcome; secondary outcomes included BD failure and clinical success. RESULTS: Standard cannulation failed in 2066/10,738(19.2%)ERCPs. aERCP and eEUS-BD were attempted in 1733 and 333 cases, respectively. After matching, 313 patients per EUS-BD group and 626 patients per aERCP group were analyzed. AEs occurred in 18.2% of aERCPs and 9.3% of eEUS-BD(p<0.01), with post-procedural pancreatitis the most frequent AE after aERCP(55 cases, 12.0%). Both regression and IPTW confirmed the robustness of these findings on the entire cohort. Technical success was significantly lower with aERCP(82.0% vs. 95.9%, p<0.01), clinical success was comparable(94.5% vs. 96.4%, p=0.89). CONCLUSIONS: In patients with DMBO and dilated CBD, eEUS-BD is associated with fewer AEs and higher technical success than aERCP, supporting its role as a safer, more effective option in DBC.