Introduction of a new model for time-continuous and non-contact investigations of in-vitro thrombolysis under physiological flow conditions
1 Department of Neurology, University Hospital of Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
2 Department of Internal Medicine, Haematology, University Hospital of Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
3 Fraunhofer Institute for Biomedical Engineering (IBMT), Ultrasound Systems Development, Ensheimer Str. 48, 66386 St. Ingbert, Germany
4 Research Centre Borstel, Clinical and Experimental Pathology, Parkallee 3a, 23845 Borstel, Germany
5 Department of Neurology, Asklepios Klinik Nord, Langstedter Landstr. 400, 22417 Hamburg, Germany
BMC Neurology 2011, 11:58 doi:10.1186/1471-2377-11-58Published: 26 May 2011
Thrombolysis is a dynamic and time-dependent process influenced by the haemodynamic conditions. Currently there is no model that allows for time-continuous, non-contact measurements under physiological flow conditions. The aim of this work was to introduce such a model.
The model is based on a computer-controlled pump providing variable constant or pulsatile flows in a tube system filled with blood substitute. Clots can be fixed in a custom-built clot carrier within the tube system. The pressure decline at the clot carrier is measured as a novel way to measure lysis of the clot. With different experiments the hydrodynamic properties and reliability of the model were analyzed. Finally, the lysis rate of clots generated from human platelet rich plasma (PRP) was measured during a one hour combined application of diagnostic ultrasound (2 MHz, 0.179 W/cm2) and a thrombolytic agent (rt-PA) as it is commonly used for clinical sonothrombolysis treatments.
All hydrodynamic parameters can be adjusted and measured with high accuracy. First experiments with sonothrombolysis demonstrated the feasibility of the model despite low lysis rates.
The model allows to adjust accurately all hydrodynamic parameters affecting thrombolysis under physiological flow conditions and for non-contact, time-continuous measurements. Low lysis rates of first sonothrombolysis experiments are primarily attributable to the high stability of the used PRP-clots.