Partially Covered Metal Stents Efficacy in Biliary Drainage of Malignant Extra-hepatic Biliary Obstruction

Malignant obstructions of the bile duct are not rare. The most common and accepted method for biliary drainage is endoscopic stent placement. There are three types of metal stents: fully covered (FC), partially covered (PC) and uncovered (U). PC-SEMS have been recently introduced and compared to FC-SEMS they seem to have a lower risk of migration, although data in the literature are discordant. Therefore the investigators will randomize the participants with biliary obstruction in 2 groups according to the type of stent used: PC-SEMS or U-SEMS. After metallic biliary stent insertion, enrolled patients will be followed for 12 months.