Bile flow through drainage catheters: an in vitro study.

An in vitro model was developed to measure bile flow at varied pressures through several commonly used transhepatic drainage catheters. As expected, larger catheters conduct more bile flow at a given pressure. All catheters studied conduct adequate amounts of bile at normal physiologic pressure gradients. The clinical observation that large catheters (10-12 French) are necessary for adequate antegrade drainage in some patients must be explained by an abnormal bile viscosity, increased duodenal pressures, or reduced biliary secretory pressure.