The Biodurability of Covering Materials for Metallic Stents in a Bile Flow Phantom

Abstract

e-PTFE tended to form biofilms more frequently than polyurethane and silicone during bile exposure. e-PTFE seemed to be less durable than silicone and polyurethane, however, as clinically applicable material because of strong absolute tensile/tear strengths.

Malignant Hilar Biliary Obstruction: Treatment by Means of Placement of a Newly Designed Y-Shaped Branched Covered Stent

“…Various kinds of covering materials, such as polyurethane, e-PTFE, and silicone, have been currently used to cover the biliary metallic stents [10,11,[18][19][20][21][22]. In our study, a silicone was used as the covering material because it is biodurable and provides a larger lumen for bile flow by means of alleviating biofilm and sludge formation [23,24].…”

Spontaneous Common Bile Duct Perforation Treated with Placement of Metal Stent

“…[7][8][9][10] One of the reasons for this may be because of differences between covering materials in membrane biodurability under long-term exposure to bile juice. 11 The reason that the stent patency period was shorter and the patency rate was lower than expected in some clinical studies of covered SEMS may be due to cracks in the covering membrane with subsequent tumor ingrowth (Fig. 3).…”

“…12,13 However, these covering materials have recently been improved, and all three materials seem to be durable for at least a 6-month period of bile exposure. 11 Meanwhile, biofilm formation with subsequent stent clogging caused by bile sludge (which is one of the unresolved problems for covered SEMS) has been a problem yet to be resolved in the clinical setting.…”

Local Delivery of Antiproliferative Agents via Stents

“…Unlike the vascular stents, there has not been much interest covering the non-vascular stents in the gastrointestinal tract with bioabsorbable polymer, since permanent polymer covering is preferred in nonvascular stents, where the biodegradation of the stent covering could result in an in-growth of the surrounding benign or malignant tissue and early obstruction of the stent [56]. Studies on the drug-eluting non-vascular stents are collected in Table 2.…”