Prevention of biliary stent clogging: a clinical review.

Endoscopic stenting is a well established treatment for obstructive jaundice. The major complication of the technique is late stent blockage, which results from bacterial biofilm and sludge deposition. Numerous approaches to overcoming this problem have been proposed. Large diameter stents can provide longer patency, but they do not prevent blockage indefinitely. Although many plastics have been investigated for resistance to biofilm adherence, there is no convincing evidence that any material prevents clogging in vivo. Changes in stent design and placement techniques to prevent bacterial colonization may provide more lasting effects. Long term antibiotic prophylaxis offers an intriguing possibility for prolonging stent patency. However, its efficacy remains uncertain, and more studies are required to assess timing, dosage, and the optimal spectrum of antibacterial coverage. Metal stent designs now permit delivery of larger diameters; these must be improved to prevent tumor ingrowth and to allow subsequent stent removal. In summary, our understanding of the behavior of bacterial biofilm and its role in stent blockage has improved, but we are still searching for methods to maintain stent function indefinitely.