Patient-Specific Fluid-Structure Interaction Simulations Suggest Wall-Shear-Stress-Related Biomarkers in Type B Dissection Associated with Marfan Syndrome

PURPOSE: Chronic type B dissection is a cardiovascular complication that occurs in the descending aorta (DSC), involving a tear at the inner wall that is present for more than three months. It can cause progressive aortic dilation, organ malperfusion, and further tearing of the aortic wall. Connective tissue disorders, such as Marfan syndrome (MFS), are associated with chronic type B dissection. Aortic diameter and growth rate are the current surveillance metrics and surgical/interventional criteria for chronic type B dissection. However, they are geometric metrics and fail to capture the hemodynamic changes that may contribute to an increased risk of adverse cardiovascular events. This study aimed to assess changes in aortic geometry and hemodynamics and investigate potential wall-shear-stress-related biomarkers to improve clinical treatment and prognostic assessment of chronic type B dissection. METHODS: Fluid-structure interaction simulations on MFS patient images before and after type B dissection were performed. Shear-stress-related metrics were quantified, and their variation over the DSC length was correlated with geometrical parameters that have been used as measures of disease progression. RESULTS: Patterns of variation over the DSC length for endothelial cell activation potential and relative residence time, two metrics that combine oscillatory shear index and time-averaged wall shear stress, correlated with maximum DSC diameter before and after dissection. Oscillatory shear index variation over the DSC length correlated with the false lumen volume index after dissection. CONCLUSION: Shear-stress-related metrics hold promise as noninvasive biomarkers for chronic type B dissection surveillance and management in MFS.