A Bacteriologic and Scanning Electron Microscope Study after Implantation of Foreign Bodies in the Biliary Tract in Rats

Abstract

Background: Bacterial adherence to the stent surfaces, concomitant colonization, and possible stent blockage are the main complications after the use of biliary stents. The present study was assigned to investigate bacteriologic and morphologic changes in the biliary tract after the implantation of biliary drain materials. Methods: Rubber and silicone pieces with a surface area of 1 cm² were implanted into the biliary 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 retrieved, cultured, and examined by scanning electron microscopy (SEM). Bacterial culture and SEM were also performed on tissue samples obtained from the mucosal surface of the biliary tract. Results: Bacterial colonization and biofilm formation were found on the surfaces of the implanted materials and on the mucosal surface of the biliary tract in animals with implants but not on the biliary tract mucosa in rats without implants. Conclusion: Foreign bodies implanted in the biliary tract facilitate bacterial adherence not only to the surface of the implants but also to the mucosal surface in the biliary tract.

Key Words:

• Bacterial adherence
• biliary drains
• biofilm
• implantation
• rubber
• silicone
• rat