Venous Thromboembolism Swine Model with Reflux Induced Venous Hypertension

This study describes a novel swine model of venous thromboembolism with reflux induced venous hypertension. Six pigs underwent disruption of the tricuspid chordae tendineae to create reflux and venous hypertension in the femoral vein. The vein was traumatized two to three weeks later by repeated withdrawal of a slightly overinflated occlusion balloon across the lumen, followed by balloon occlusion of the outflow. A small amount of Thrombin was injected into the traumatized vein segment immediately after outflow occlusion. Thrombosis of the traumatized vein evolved into an organized thrombus seven weeks later. The histological features of the harvested post-thrombotic femoral vein were studied with Hematoxylin and Eosin and Trichrome stains. In all six pigs, initial disruption of the chordae tendineae was successfully performed to create tricuspid reflux and venous hypertension. After two-stage sequential procedures, a thrombus formed in the target femoral vein segment. Histology of the harvested thrombotic vein showed features of an organizing thrombus with collagen formation and fibrosis. The novel swine venous thromboembolism model may serve as a platform for developing and testing human-sized therapeutic procedures and devices in translational venous research.