The Effect of Aspirin on Patency of Metal Stent in Malignant Distal Bile Duct Obstruction

The aim of this study is to determine whether administration of aspirin can help maintain the patency of metallic stents for distal malignant common bile duct obstruction. Metal stents are mainly used for malignant biliary obstruction if the surgical treatment is not considered and its maintenance period has been reported to be about 8 months. This study will be prospectively conducted as a randomized controlled study with aspirin treated patients who received metal stents in patients over 20 years who were confirmed malignant distal biliary obstruction. The primary endpoint is the incidence of stent dysfunction in both groups for 6 months after the procedure. The secondary endpoints included duration of metallic stent patency, incidence of further procedures, and adverse events related with aspirin.