Hemodynamics of type-B aortic dissection
Type-B aortic dissections are complex vascular lesions in which the layers of the descending aorta separate, forming a true and false lumen for blood flow. These lesions are complex to manage with a 23% post-discharge mortality with medical treatment alone. Our laboratory is interested in understanding the role of anatomical differences in type-B aortic dissections, the relationship between anatomy and 3D flow flow dynamics, and the impact of flow dynamics on the potential for rupture.
Ex-vivo model of aortic dissection
To create various anatomical sub-types of type-B aortic dissection and investigate the hemodynamics, we developed a physiological flow simulator in which porcine aorta's can be studied under pulsatile flow conditions. In this flow model, we are investigating the impact of single vs. multiple entry tears, entry and re-entry tears, partial thrombosis of the false lumen and the impact of TEVAR on the true and false lumen flow dynamics.
In-vivo model of aortic dissection
We developed a swine model of type-B aortic dissection, by surgically separating the intimal and medial layers of the aorta with aortic cross clamping for few minutes. The mean arterial pressure was maintained higher than normal, and propagation of the dissection to the sub-diaphragmatic parts, distal to the renal artery was observed on IVUS imaging. Acute outcomes with this model have been excellent, but rupture of the aorta on POD 3-7 was observed, providing a reasonable window to investigate the mechanical changes that occur in the false lumen to cause spontaneous rupture of the aorta. The impact of TEVAR on these changes can be assessed in this model of t-BAD.