Biliary drainage catheters fluid dynamics: In vitro flow rates and patterns

Percutaneous internal-external biliary drainage catheters restore biliary flow in case ofbiliary obstruction by channeling bile from the intrahepatic ducts into the duodenum. Bileis presumed to enter the side holes proximal to the obstruction and flow through the lumenof the catheters, bypassing the obstruction around the bile duct [1]. However, biliary flowmay occur within the lumen of the biliary catheter or stent or around their shafts [2].Repeated clinical observations of biliary catheter placement and cholangiograms havedemonstrated the presence of contrast in the duodenum without contrast in the distalcatheter side holes, which suggests that bile flow may occur around the catheter shaftinstead of or in addition to within its lumen. Furthermore, biliary catheters with multipleside holes do not necessarily improve flow rates and may facilitate encrustation with debristhat could lead to catheter obstruction and sepsis [3].The purpose of this study was to evaluate the flow rates and flow patterns of simulatedbile through drainage catheters in an in vitro biliary system model.