A BACTERIOLOGICAL AND SCANNING ELECTRON-MICROSCOPE STUDY AFTER IMPLANTATION OF FOREIGN-BODIES IN THE BILIARY-TRACT IN RATS

Background: Bacterial adherence to the stent surfaces, concomitant col onization, and possible stent blockage are the main complications afte r the use of biliary stents. The present study was assigned to investi gate bacteriologic and morphologic changes in the biliary tract after the implantation of biliary drain materials. Methods: Rubber and silic one pieces with a surface area of 1 cm(2) were implanted into the bili ary tract in rats after temporary obstruction of the common bile duct by the use of a mini-occluder. The animals were killed at 4, 8, and 14 weeks, respectively, after implantation, and the implants were retrie ved, cultured, and examined by scanning electron microscopy (SEM). Bac terial culture and SEM were also performed on tissue samples obtained from the mucosal surface of the biliary tract. Results: Bacterial colo nization and biofilm formation were found on the surfaces of the impla nted materials and on the mucosal surface of the biliary tract in anim als with implants but not on the biliary tract mucosa in rats without implants. Conclusion: Foreign bodies implanted in the biliary tract fa cilitate bacterial adherence not only to the surface of the implants b ut also to the mucosal surface in the biliary tract.