A new in vitro thrombogenicity test for medical tubes.

Basic information on the affected coagulation behaviour of healthy human blood passing foreign artificial surfaces is of immense importance for a safe clinical therapy. An in vitro screening method is presented which tests the thrombogenicity of medical tubes, applying the clinically already established resonance thrombography (RTG). Several medical tubes with various types and contents of plasticizers are tested and compared with materials free of additives. The effect of the release of ingredients is indicated by this procedures, as well as the influence of a sterilizing treatment with gamma-radiation on the physical surface properties, such as smoothness. In all cases, the modified RTG method proves its suitability and sensitivity. In addition, this method allows accurate adjustment of the extrusion parameters for tube manufacturers.