There are two types of biliary stents: 1) the plastic stent made from polyethylene or polytetrafluoroethylene; and, 2) the metal stent braided in the form of a tubular mesh from surgical-grade stainless steel alloy and designed to expand to a maximum diameter of 10 mm. The main drawback of the plastic stent is the relatively high occlusion rate, but its advantage is the lower cost. The use of a metal stent for hilar tumor has many theoretical advantages: 1) the flexible open-mesh design should allow drainage of secondary duct branches; and, 2) its larger diameter may provide better drainage and longer patency (~3-9 months).