In Vivo Monitoring of Venous Thrombosis in Mice.

Abstract 5061

Venous thromboembolism afflicts 117 people per 100,000 each year and is an important cause of morbidity and mortality. There has been extensive research dedicated to the clinical aspect of venous thrombosis, especially with regards to its diagnosis and treatment. However, animal models studying this phenomenon are scarce and, in most cases, very crude. Developing a murine model of venous thrombosis using techniques similar to the ones used to detect thrombosis in humans can be a constructive step in studying this phenomenon in more detail. The model developed in our lab uses ultrasound imaging to visualize venous clots in the Inferior Vena Cava (IVC) of mice, allowing for precise measurements of the formed clot. Ligation of the IVC is one of the well established models for studying thrombosis in mice. We ligated the IVC of wild type C57B6 mice, and allowed them to recover. We then followed clot formation at several time points after the operation using micro-ultrasonography, the Vevo 770®, a novel imaging ultrasound technology designed to monitor murine vasculature. To assess the precision of the clot measurements, we then sacrificed the mice, and dissected out the thrombi in order to precisely measure and weigh them. A thrombosis develops only after 5 hours of ligation post surgery when a clot is visualized in the IVC. The clot increases slightly over the next 24 hours. The measurements of the clot after dissection correlates favourably with the measurements done by ultrasonagraphy using the Vevo770®. These data suggest that the Vevo770® can be used as a reliable technique for non-invasive assessment of venous thromboembolism in mice. Developing a murine model for thrombosis using more accurate, and clinically more relevant techniques such as ultrasonography, is a step towards better understanding and treatment of venous thromboembolism.