Covered verses uncovered stents for malignant common bile duct obstruction, which lasts longer?

The often taught convention that covered biliary stents stay open longer than their bare relatives may not be true. Researchers from Seoul, South Korea are challenging this, finding that uncovered stents had significantly longer patency in their subjects. Although limited by a small sample size of 20 patients in each arm, this prospective randomized study found that the uncovered stents had a mean patency of 413 days, double that of the covered ones at 208 days.

Covered stents were always thought to have better patency because of their ability to avoid tumor ingrowth, a theory that was previously supported by several randomized studies. After finding the opposite, the authors of this study theorize that pores on the surface of the covered stent act to promote bacterial colonization and biofilm development, in turn leading to slower bile flow. Nevertheless, the authors found no survival benefit for either stent.


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Kaplan-Meier graph showing cumulative stent patency. Cumulative stent patency was significantly higher in the uncovered metallic stent versus the covered metallic stent group (P = .041, log-rank test).




Stent occlusion by sludge. (a) Percutaneous cholangiography performed after 10 mm × 80 mm Niti-S covered stent placement. The stent is not yet fully dilated. (b) Cholangiography performed 2 months after stent placement showed multiple filling defects (arrows), suggesting debris. Debris and food material were confirmed by saline irrigation.


Citation: Lee, S. J. et al. Comparison of the Efficacy of Covered versus Uncovered Metallic Stents in Treating Inoperable Malignant Common Bile Duct Obstruction: A Randomized Trial. Journal of Vascular and Interventional Radiology (2014). doi:doi: 10.1016/j.jvir.2014.05.021


Post author: Amish Patel, MD