A Pilot Study Characterizing Flow Patterns in the Thoracic Aorta of Patients With Connective Tissue Disease: Comparison to Age- and Gender-Matched Controls via Fluid Structure Interaction

Figure 1. Time-averaged wall shear stress (TAWSS) distributions for the six patients with the various connective tissue diseases studied (top row) and age- and gender-matched control participants to which each was compared (bottom row). The size of the models displaying the TAWSS results shown is relative to each other using the descending aortic outlet dimensions. Data in Figures 2, 4 are presented along the length of the aorta. This distance was made consistent between patients and control participants using dimensional information from imaging data and then normalized from 0 to 1 as shown beside the model and TAWSS from the leftmost control participant.

Figure 2. Local quantification of TAWSS results. The top row shows histograms (2 dyn/cm2 bins) of the area (cm2) from each model surface exposed to TAWSS values from 0 to 50 dyn/cm2 (connective tissue disease = solid bars; age- and gender-matched controls = hollow bars). Longitudinal TAWSS distributions along the outer, anatomic right, anatomic left, and inner curvatures of the aorta are also shown in subsequent rows for the patients with various connective tissue disease (dashed lines) vs. their associated age- and gender-matched controls (solid lines). Low TAWSS is generally thought to promote atherogenesis, so skewing of histogram results toward lower values could be interpreted as less ideal, as could overall lower values of TAWSS along the aortic surfaces.

Figure 3. Distributions of oscillatory shear index (OSI) for the six patients with the various connective tissue diseases studied (top row) and age- and gender-matched control participants to which each was compared (bottom row). The size of the models displaying the OSI results shown is relative to each other using the descending aortic outlet dimensions.

Figure 4. Local quantification of oscillatory shear index (OSI) results. The top row shows histograms (0.2 unit bins) of the area (cm2) from each model surface exposed to OSI values from 0 to 0.5 (connective tissue disease = solid bars; age- and gender-matched controls = hollow bars). Longitudinal OSI distributions along the outer, anatomic right, anatomic left, and inner curvatures of the aorta are also shown in subsequent rows for the patients with various connective tissue disease (dashed lines) vs. their associated age- and gender-matched controls (solid lines). Higher OSI values are generally thought to promote atherogenesis, so skewing of histogram results toward higher values could be interpreted as less ideal, as could overall higher values of OSI along the outer, anatomic right, anatomic left, and inner curvatures of the aorta.