Technical failure in ERCP for malignant biliary strictures remains a major determinant of patient outcome and procedural quality. This study aimed to identify robust, real-life predictors of technical failure using universally available anatomical and procedural variables, with the goal of guiding strategy in high-risk malignant obstruction.

All index ERCPs performed for malignant biliary obstruction (2017–2023) were retrospectively reviewed. Technical failure was defined as the inability to achieve selective biliary cannulation or complete intended drainage. Candidate predictors included stricture level, intrahepatic duct dilation, completeness of cholangiogram, baseline bilirubin, and papillary anatomy. Independent predictors were identified using multivariable logistic regression.

Among 510 patients (mean age 66 ± 13 years; 51% male), technical success was achieved in 94.8%. Failures occurred predominantly in proximal or extensive hilar strictures. Incomplete cholangiogram was the strongest predictor of technical failure (adjusted OR ≈ 7.5), followed by absence of intrahepatic duct dilation (adjusted OR ≈ 5.8). Markedly elevated baseline bilirubin (> 300 µmol/L) was also associated with higher failure rates. Papillary distortion showed a weaker but consistent association.

Technical failure during malignant ERCP follows a reproducible anatomical pattern rather than procedural variability. Three high-risk features—incomplete cholangiogram, non-dilated ducts, and severe cholestasis—characterize nearly all failures and should prompt upfront adaptation of drainage strategy. Anticipating rather than managing failure aligns directly with ESGE quality principles and enhances the safety and effectiveness of malignant biliary drainage in routine practice.