Benign Biliary diseases

The standard endoscopic therapy for benign biliary disease has been plastic stent insertion. For biliary leaks, a single stent will suffice in over 90% of instances with a single treatment session. Postoperative strictures and strictures due to chronic pancreatitis have a higher failure rate and have led to the use of multiple stents which are placed in a sequential fashion on the premise that the radial diameter achieved will result in less restricturing but at the cost of more procedures. The increased radial diameter of self-expanding metal stents (SEMS) has led to their use in instances where plastic stents have failed. Uncovered SEMS (uSEMS) had some initial success reported, but over time, occlusion due to mucosal hyperplasia and extraction difficulties became more of a problem. This has led to stent redesign with a covering membrane to prevent ingrowth and the hyperplastic reaction and to improve the removability of the device and offset the increased cost by reduction of the number of procedures needed to reach a therapeutic endpoint. The mechanical properties of these new devices are highly variable and may lead to problems such as spontaneous migration, new stricture formation, and imbedding into the duodenal wall. Almost all of the data available to date consists of case series, and no prospective, randomized, controlled trials comparing multiple plastic stents to covered stents have been reported. The current recommendation is that plastic stents should be the first line of therapy and that SEMS be considered for failure of primary treatment.