Expandable metal stents for malignant biliary obstruction

Abstract

Malignant obstruction of the biliary tree results in jaundice, pruritus, and cholangitis. Malignant biliary obstruction is associated with a poor prognosis. Palliation of the symptoms of malignant biliary obstruction is an important part of patient management. Endoscopic stent placement achieves safe, rapid, and effective relief from malignant biliary obstruction in nearly all patients. Endoscopic therapy is generally preferred over surgical and percutaneous alternatives. Fixed-diameter plastic endobiliary stents have proven highly successful for establishing inital drainage of the obstructed bile duct. However, plastic stent occlusion, resulting in recurrent jaundice and cholangitis, occurs in many patients. Occlusion is in part caused by the limited fixed diameter of plastic stents, which can be no greater than the diameter of the accessory channel of the duodenoscope used for placement. Self-expanding metallic stents (SEMS) were developed to overcome this limitation. SEMS are made from a variety of materials and in a variety of configurations and sizes. They can be placed while constrained on a narrow-diameter introducer system and deployed to expand to up to a 10-mm diameter. This article reviews the most widely used SEMS for biliary obstruction and provides SEMS placement and clinical experiences.