[Thrombogenicity of central venous catheters: comparison of two polyurethane catheters]

Thrombosis represents a possible catheter-related risk. Beside many endogenous and exogenous factors, the material as well as its condition do have a decisive influence on thrombogenicity. One factor of thrombogenicity is the surface of the catheter. Therefore, two different types of polyurethane catheters were compared according to their surface structure by electron microscopy. Furthermore, an in vivo testing should confirm a possible, different thrombogenicity.

A model with a single aperture at the catheter tip and a model with multiple apertures were tested. We compared the electron-microscopic pictures of specific areas which were expected to cause problems. Thrombogenicity in the vena cava inferior was tested in 20 rabbits. For statistical evaluation the Wilcoxon U test was used.

Polyurethane catheters have a smooth and homogeneous surface inside and outside of the catheter. However, there are many production-related, qualitative differences in the morphology of the apertures. The model with multiple apertures and a closed catheter tip turned out to have a much more irregular surface compared to the model with a single aperture. In vivo testing showed that each catheter causes thrombosis, independent of the type. The catheter with multiple apertures proved to have no advantages as far as thrombogenicity is concerned; catheter-specific complications of this type are possible. Also, atraumatic insertion by means of Seldinger's technique is not possible using a catheter with a closed tip.

The catheter with multiple apertures does not have any advantages to the catheter with a single aperture.