J. Alvikas1, S. Haldeman1, A. Hassoune1, J. D. Latoche2, C. J. Anderson2, M. D. Neal1 1University of Pittsburgh Medical Center,Department Of Surgery,Pittsburgh, PA, USA 2University of Pittsburgh,Department Of Medicine,Pittsburgh, PA, USA
Introduction: Venous thromboembolism (VTE), comprised of deep venous thrombosis and pulmonary embolism, is a major cause of cardiovascular morbidity and mortality worldwide. Previous studies have utilized the inferior vena cava (IVC) ligation model to induce the thrombus and harvest it at specific timepoints for quantification and analysis. However, for better understanding of VTE development, it is important to study the dynamics of thrombus formation. In this study, we demonstrate that it is feasible to utilize the preclinical micro computed tomography (microCT) to quantify the evolution of venous thrombosis.
Methods: C57BL/6 wild-type mice (n=9) were subjected to IVC ligation to induce thrombus formation. At 1 hour, 3 hours, 6 hours and 24 hours post-IVC ligation, four animals were anesthetized with 2% isoflurane and injected with 100µL of Fenestra VC, an iodinated lipid emulsion-based contrast dye designed for preclinical angiography. Five animals were injected only at the 24-hour timepoint. Siemens Inveon PET/CT scanner was utilized for microCT. After imaging was complete, mice were sacrificed and thrombi were harvested and weighed. Inveon Research Workplace (IRW) was utilized for image processing and volumetric analysis and Prism GraphPad were used for data analysis.
Results: IVC thrombi were successfully imaged and quantified as all 4 timepoints. Clot weights and volumes showed strong linear relationship (R2=0.877, p=0.0002). Mean clot volumes were 2.52mm3, 8.46mm3, 10.98mm3 and 8.78mm3 at 1 hour, 3 hours, 6 hours and 24 hours, respectively. Three thrombi could already be visible at 1-hour timepoint, one thrombus was detected only at 24 hours and was 1.2mm3.
Conclusion: The present data demonstrates that microCT can be successfully utilized to image IVC thrombus formation in the murine model of VTE. This approach allows for thrombus quantification, the study of the dynamics of venous thrombus growth and may be useful in dissecting molecular mechanisms underlying the different stages of VTE.
