Cefotaxime-Eluting Covered Self-Expandable Stents in a Canine Biliary Model: Scanning Electron Microscopic Study of Biofilm Formation

Abstract

As bacterial attachment and subsequent biofilm formation on the surface of a stent lumen may be important in initiating sludge formation and subsequent stent blockage, there is a need for antibiotic-eluting stents to prevent sludge formation by bacterial attachment and colonization. To evaluate the antimicrobial effects of cefotaxime-eluting covered self-expandable stents (CE-CSEMS) in a canine biliary model by using scanning electron microscopy (SEM) to analyze biofilm formation on the inner surface of the stents. Three 10% (wt/vol) CE-CSEMS, three 20% (wt/vol) CE-CSEMS, and three control stents (CS) were endoscopically inserted into the bile ducts of nine mongrel dogs, which were followed up for 8 weeks. Gross and SEM examinations were performed to access the development and degree of biofilm formation in dogs with CS and CE-CSEMS. All stents were successfully inserted into canine bile ducts without any procedure-related complications. All nine dogs remained in good health without jaundice over the next 8 weeks. The degree of biofilm was similar in dogs implanted with CS and CE-CSEMS using two concentrations of cefotaxime either by gross inspection or SEM. All stent types showed a similar biofilm structure with relatively uniform thickness on SEM. Cefotaxime does not prevent biofilm development in a canine biliary model. Biofilm formation on the inner surface of biliary stents may be prevented by using broad-spectrum antimicrobial agents and stents that maintain a steady release of these agents for a long time, thus prolonging stent patency.