Abstract
A biofilm is a community of microbial cells which are enclosed in an external matrix and separated by a network of water channels attached to natural or artificial surfaces. Biofilms formed inside biliary stents consist of a mixed spectrum of bacterial communities, most of which usually originate from the intestines. The patency of biliary stents is the most important problem. Stent occlusion can threaten the health and even life of patients. The main cause of this phenomenon is bile sludge, which is an excellent environment for the multiplication and existence of microorganisms. Due to the great clinical importance of maintaining the patency of biliary stents, several methods have been developed to prevent the accumulation of sludge and the subsequent formation of biofilm; these include, among others, the use of anti-adhesive materials, coating the inner surface of stents with metal cations (silver, copper) or other antimicrobial substances, the implementation of biodegradable drug-eluting biliary stents and the development of a new stent design with an anti-reflux effect. This article presents the latest information on the formation of biofilms in biliary stents, as well as historical and future methods of prevention.