Novel Animal Model of Large Vessel Venous Thromboembolism to Assess the Effectiveness of Thrombus Removal Therapies

Background: Venous thromboembolic disease, including deep vein thrombosis and pulmonary embolism, accounts for nearly 180,000 deaths annually in the United States. It is the third most common cause of cardiovascular morbidity and mortality, and is usually caused by a thromboembolism of a large vessel like the pulmonary artery or ilio-caval vein. Objectives: In order to develop more effective treatments for the thromboembolic disease in these large vessels, animal models are necessary. Previous research has been primarily focused on using murine models, which has aided in developing novel pharmacological therapies; however, given the limited size of the large vessels in these models, they are not representative of the clinical presentation in humans. Methods: A venous blood sample from a Yucatan pig was coagulated in in-vitro and subsequently introduced via the femoral vein. Complete occlusion and cessation of flow across the posterior vena cava was established. A novel infusion catheter-Bashir™ Endovascular Catheter-was advanced into the thrombotic vena cava. The infusion basket was expanded, thrombolysis was initiated, and results were documented by sequential venograms. Thereafter, the catheter was positioned in the pulmonary artery to evaluate pulmonary artery pressures and mixed venous oxygen saturations. Results and Conclusion: We successfully developed a novel animal model in which we cause a large vessel occlusion by introducing a thrombus into the posterior vena cava. Subsequently, we restored the venous flow by percutaneously dissolving the thrombus using a novel infusion catheter. We believe this model will aid in the development and evaluation of future thrombus reduction therapies