Endoscopy 2005; 37(8): 729-734
DOI: 10.1055/s-2005-870131
Original Article
© Georg Thieme Verlag KG Stuttgart · New York

Mechanisms of Biliary Stent Clogging: Confocal Laser Scanning and Scanning Electron Microscopy

A.  M.  van Berkel1 , J.  van Marle2 , A.  K.  Groen1 , M.  J.  Bruno1
  • 1Dept. of Gastroenterology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
  • 2Dept. of Electron Microscopy, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
Further Information

Publication History

Submitted 19 July 2004

Accepted after Revision 4 February 2005

Publication Date:
20 July 2005 (online)

Background and Study Aims: Endoscopic insertion of plastic biliary endoprostheses is a well-established treatment for obstructive jaundice. The major limitation of this technique is late stent occlusion. In order to compare events involved in biliary stent clogging and identify the distribution of bacteria in unblocked stents, confocal laser scanning (CLS) and scanning electron microscopy (SEM) were carried out on two different stent materials - polyethylene (PE) and hydrophilic polymer-coated polyurethane (HCPC).
Patients and Methods: Ten consecutive patients with postoperative benign biliary strictures were included in the study. Two 10-Fr stents 9 cm in length, one made of PE and the other of HCPC, were inserted. The stents were electively exchanged after 3 months and examined using CLS and SEM.
Results: No differences were seen between the two types of stent. The inner stent surface was covered with a uniform amorphous layer. On top of this layer, a biofilm of living and dead bacteria was found, which in most cases was unstructured. The lumen was filled with free-floating colonies of bacteria and crystals, surrounded by mobile laminar structures of mucus. An open network of large dietary fibers was seen in all of the stents.
Conclusions: The same clogging events occurred in both PE and HCPC stents. The most remarkable observation was the identification of networks of large dietary fibers, resulting from duodenal reflux, acting as a filter. The build-up of this intraluminal framework of dietary fibers appears to be a major factor contributing to the multifactorial process of stent clogging.

References

  • 1 Huibregtse K, Tytgat G N. Palliative treatment of obstructive jaundice by transpapillary introduction of large bore bile duct endoprosthesis.  Gut. 1982;  23 371-375
  • 2 Davids P H, Groen A K, Rauws E A. et al . Randomised trial of self-expanding metal stents versus polyethylene stents for distal malignant biliary obstruction.  Lancet. 1992;  340 1488-1492
  • 3 Groen A K, Out T, Huibregtse K. et al . Characterization of the content of occluded biliary endoprostheses.  Endoscopy. 1987;  19 57-59
  • 4 Sung J Y, Leung J W, Shaffer E A. et al . Bacterial biofilm, brown pigment stone and blockage of biliary stents.  J Gastroenterol Hepatol. 1993;  8 28-34
  • 5 Coene P P, Groen A K, Cheng J. et al . Clogging of biliary endoprostheses: a new perspective.  Gut. 1990;  31 913-917
  • 6 Leung J W, Ling T K, Kung J L, Vallance-Owen J. The role of bacteria in the blockage of biliary stents.  Gastrointest Endosc. 1988;  34 19-22
  • 7 Speer A G, Cotton P B, Rode J. et al . Biliary stent blockage with bacterial biofilm: a light and electron microscopy study.  Ann Intern Med. 1988;  108 546-553
  • 8 McAllister E W, Carey L C, Brady P G. et al . The role of polymeric surface smoothness of biliary stents in bacterial adherence, biofilm deposition, and stent occlusion.  Gastrointest Endosc. 1993;  39 422-425
  • 9 Dowidar N, Kolmos H J, Matzen P. Experimental clogging of biliary endoprostheses: role of bacteria, endoprosthesis material, and design.  Scand J Gastroenterol. 1992;  27 77-80
  • 10 Jansen B, Goodman L P, Ruiten D. Bacterial adherence to hydrophilic polymer-coated polyurethane stents.  Gastrointest Endosc. 1993;  39 670-673
  • 11 Binmoeller K F, Seitz U, Seifert H. et al . The Tannenbaum stent: a new plastic biliary stent without side holes.  Am J Gastroenterol. 1995;  90 1764-1768
  • 12 Van Berkel A M, Boland C, Redekop W K. et al . A prospective randomized trial of Teflon versus polyethylene stents for distal malignant biliary obstruction.  Endoscopy. 1998;  30 681-686
  • 13 Costamagna G, Mutignani M, Rotondano G. et al . Hydrophilic Hydromer-coated polyurethane stents versus uncoated stents in malignant biliary obstruction: a randomized trial.  Gastrointest Endosc. 2000;  51 8-11
  • 14 Van Berkel A M, Bruno M J, Bergman J J. et al . A prospective randomized study of hydrophilic polymer-coated polyurethane versus polyethylene stents in distal malignant biliary obstruction.  Endoscopy. 2003;  35 478-482
  • 15 Lawrence J R, Neu T R, Swerhone G DW. Application of multiple parameter imaging for the quantification of algal, bacterial and exopolymer components of microbial biofilms.  J Microbiol Methods. 1998;  32 253-261
  • 16 Sung J J, Sollano J D, Lai C W. et al . Long-term ciprofloxacin treatment for the prevention of biliary stent blockage: a prospective randomized study.  Am J Gastroenterol. 1999;  94 3197-3201
  • 17 Weickert U, Venzke T, Konig J. et al . Why do bilioduodenal plastic stents become occluded. A clinical and pathological investigation on 100 consecutive patients?.  Endoscopy. 2001;  33 786-790

M. Bruno, M. D., Ph. D.

Dept. of Gastroenterology and Hepatology C2 - 220

Academic Medical Center · Meibergdreef 9 · 1105 AZ Amsterdam · The Netherlands

Fax: +31-20-6917033

Email: m.j.bruno@amc.uva.nl