Impact of sphincterotomy on suprapapillary inside stent patency in unresectable malignant hilar biliary obstruction: a multicenter cohort study

Background and study aims: The role of endoscopic sphincterotomy (EST) during suprapapillary inside stent placement for unresectable malignant hilar biliary obstruction (MHBO) remains uncertain. We evaluated its association with stent patency and adverse events. Patients and methods: This multicenter retrospective cohort included 376 consecutive patients treated at eight institutions (2014–2024). The primary outcome was time to recurrent biliary obstruction (TRBO). Multivariable Cox regression, 1:1 propensity score matching (PSM), and competing-risk analysis were performed. Patients with prior EST were excluded from index-procedure safety analyses.