The role of the contrast medium viscosity in the adequacy of operational cholangiography.

The viscosity of some routine hydrosoluble contrast media used in operational cholangiography (Bilignost and Verographin) was studied. The different viscosity of hepatic and vesical bile and of the contrast media was determined. This fact shows that the data of any direct cholangiography in accordance with the law of Hagen-Poiseuille is misinterpreted. As a result it may lead to a wrong surgical procedure, for example, sphincterotomy, and vice versa.