The role of polymeric surface smoothness of biliary stents in bacterial adherence, biofilm deposition, and stent occlusion.

Bacterial adherence and biofilm deposition onto the surface of polymers used for biliary stents are the initial events that ultimately lead to stent occlusion. Vivathane is a new polymer with an ultrasmooth surface. In this study, stents made from Vivathane were compared to standard plastic stents in an in vitro model. Polyethylene, C-flex, and Vivathane stents were connected in parallel and perfused with infected bile. The surfaces of the polyethylene and C-flex stents developed exuberant bacterial growth and biliary sludge deposition. Vivathane stents were nearly free of bacteria and demonstrated no propensity for biliary sludge deposition. These results indicate that polymeric surface irregularities promote bacterial adherence, biofilm deposition, and accumulation of biliary sludge. The ultrasmooth surface of Vivathane does not allow bacterial adherence and biofilm deposition. Vivathane holds promise as a new polymer for use in biliary stents in long-term applications.