Morphological and hemostatic changes in rats with abdominal arterial prosthesis.

We evaluated the changes over time in hemostatic factors during ongoing arterial thrombosis in rats, as induced by a loop-shaped aortic prosthesis. Moreover, we investigated this condition by inspecting in parallel local thrombus growth, systemic vascular prostacyclin and t-PA production. One minute after loop insertion, activated platelets spread on the internal surface of the prosthesis and 24 hrs later numerous platelet aggregates supported by a fibrin network could be observed. However, no evidence for platelet activation could be concomitantly found in peripheral blood. A sustained increase in PGI2 formation was detected together with a progressive increase in plasma fibrinolytic activity during thrombus growth. The levels of fibrinogen as well as antithrombin III (ATIII) and heparin cofactor II (HCII) activities were steadily increased in loop-bearing animals. In conclusion, the dynamic phases of thrombus formation, in an aortic prosthesis, produce changes in vascular function and in hemostatic factors at the level of systemic blood.