Hemodynamic Effects of Entry Versus Exit Tear Size and Tissue Stiffness in Simulations of Aortic Dissection

Abstract

Based on the patient-specific model of a Type B aortic dissection we created a second model with reduced entry and exit tear size. Two sets of simulations were performed for each model: (i) fluid structure interaction (FSI) and (ii) rigid wall simulations. In both simulation modalities we found that alterations in tear size had substantial impact on true to false lumen flow ratios, true and false lumen pressure differences, and loss of systolic pressure along the dissection. Compared to rigid wall simulations, FSI simulations yielded decreased true lumen flow ratios, increased dampening of flow waveforms along the aorta, smaller negative pressure differences in the distal dissection, and smaller systolic pressure drops across entry and exit tears. These results underline the sensitivity of simulation-based quantitative hemodynamics in aortic dissections to tear size and tissue stiffness.