ENDOSCOPIC STENTING FOR PALLIATION OF MALIGNANT BILIARY OBSTRUCTION -A REVIEW OF PROGRESS IN THE LAST 15 YEARS

Since the late 1970s, endoscopic biliary stenting has become a standar d palliative treatment for obstructive jaundice due to malignancies of the pancreas and the hepatobiliary system. Despite the high initial s uccess rate in achieving biliary drainage, endoscopic stenting therapy has been limited by the clogging of biliary stents, usually after fou r to five months, due to formation of adherent bacterial biofilm and a ccumulation of biliary sludge. Various methods for the prevention of b acterial adhesion and prolongation of stent patency have been investig ated, including prophylactic antimicrobial agents and bile salts, new stent materials, and new stent designs. Recently, the introduction of self-expandable metal stents has significantly improved the duration o f stent patency but the cost is considerably higher. Each method has i ts own merits as well as specific problems. This article reviews the p athogenesis of biofilm formation on the biliary stents and the latest status of research in avoiding stent occlusion.