An experimental model of early-chronic iliac vein thrombosis with occlusion coils and thrombin.

Purpose: To create an early chronic venous thrombosis with good comparabili ty to human venous thrombosis for evaluation of new thrombectomy systems. M ethods: Using a transjugular approach, three dacron-fibered occlusion coils were placed into the proximal common iliac vein of 7 pigs under general an esthesia. The coiled common iliac vein was blocked by the use of a balloon occlusion catheter, and 500 units of thrombin were injected into the "coil basket". One hour later, the ballon catheter was deflated and removed. Afte r three days, the thrombus was controlled by phlebography and histology. Re sults: The induction of thrombi was successful in all cases. The mean lengt h of the thrombi was 60 mm and the mean diameter was 10 mm. Histologically, the thrombus consisted of a laminated plug of fibrin and platelets as well as clots in the sense of a mixed thrombus with signs of a beginning organi zation. Considering the cellular composition and the histological aspect, t he thrombi met the criteria for early chronic venous thrombosis in humans. Conclusion: The presented experimental thrombus model is easy to perform an d enables a good comparability to early chronic human venous thrombosis.