Duration and Predictive Factors of Plastic Biliary Stent Patency: Results of a Large Prospective Database Analysis

<b>Background/Objectives</b>: Endoscopic retrograde cholangiopancreatography (ERCP) with biliary stent placement is a mainstay of current management for biliary obstruction, with stent occlusion being the most common and severe complication. The mechanism of stent occlusion is well known; however, factors affecting individual stent patency are still controversial. The objective of this study was to determine the duration and factors affecting plastic biliary stent patency. <b>Methods</b>: We conducted a retrospective analysis of the consecutive procedures of endoscopic retrograde cholangiopancreatography (ERCP) and biliary stent placement in a single tertiary center during the period of 2010-2019. The primary outcome of the study was the time of stent patency. Secondary outcomes were the development of cholangitis upon re-stenting and whether subsequent re-stenting was emergent. Re-stenting was considered <i>emergent</i> if it happened before the planned elective re-stenting date, irrespective of indication (development of cholangitis, rising jaundice, suspected dislodgement, etc.). <b>Results</b>: Between 2010 and 2019, a total of 5462 ERCP procedures were performed, with 2659 resulting in plastic biliary stent placement. On average, the plastic biliary stent was patent for 63 (25, 96) days with significant differences between the indications for ERCP groups. The strongest risk factors for the development of cholangitis upon re-stenting was cholangitis during index ERCP (HR = 1.83; 95% CI: 1.48-2.27; <i>p</i> < 0.001), intrabiliary malignancy being the indication for stenting (HR = 1.34; 95% CI: 1.12-1.60; <i>p</i> < 0.001) and increasing number of stents being placed (HR = 1.73; 95% CI: 1.27-2.36; <i>p</i> < 0.001). <b>Conclusions</b>: Patients with an underlying malignancy, history of cholangitis, and multiple biliary stents are at an increased risk for stent occlusion and cholangitis, warranting a tailored stent exchange interval to prevent complications.