In vitro long-term perfusion of different materials for biliary endoprostheses.

An in vitro perfusion of Teflon, polyethylene, polyurethane, and Percuflex TM catheters with human bile was performed to estimate the incrustation rate of the different materials. Microscopic and chemical analyses revealed the highest incrustation rate on Teflon and the lowest on polyurethane (about four times lower than on Teflon). For each material the probable minimum value for the duration of patency of an endoprostheses of a 3-mm inner diameter was calculated.