Bile Viscosity in Patients with Biliary Drainage. Effect of Co-trimoxazole and N-acetylcysteine and Role in Stent Clogging

Background: The main disadvantage of endoscopic insertion of an endoprosthesis is the tendency of the stent to clog after a few months. In this study we determined the role of bile viscosity in stent clogging.

Methods: Sixty patients were stented with 10 Fr 11-cm stents. The stents were electively removed after 2 months, and a bile sample was obtained simultaneously. Bile viscosity was measured with a coaxial rotation viscometer. The influence of treatment with antibiotics and a mucolytic agent on viscosity was assessed in a randomized trial.

Results: Bile viscosity correlated significantly with DNA and total protein concentration. After treatment with either N-acetylcysteine or co-trimoxazole a lower mean value of the viscosity was observed, but this was not statistically significant. There was no correlation between bile viscosity and the amount of sludge adhering to the stents.

Conclusions: In most patients bile viscosity plays a limited role in stent clogging. Only in patients with excessively high viscosity do mucolytic agents or treatment with antibiotics seem to have a role.