Association of hemodynamics and morphology with local surface growth of abdominal aortic aneurysm using spatial pattern analysis

The study aims to investigate the relationship between morphology, hemodynamics, and local growth that could explain biomechanical mechanism of the abdominal aortic aneurysm (AAA) progression. We analyzed a sequential pairs of computerized tomography angiography images from 25 patients to extract multiphysical features, including local growth, lumen remodeling, intraluminal thickness, aneurysm radii, time-averaged wall shear stress, and oscillatory shear index. We used vascular deformation mapping technique for local growth assessment, which was validated against anatomical landmarks and demonstrated strong correlation with growth metrics. Among the extracted parameters of AAA, we conducted spatial correlation analysis based on subsampling with decorrelation length. The key findings of this study are identified relationships between blood flow dynamics and lumen remodeling, and positive correlation between initial thrombus thickness and aneurysm growth, supported by both local and global correlation analysis. We classified the blood flow patterns into three types and found no statistically significant differences in the distribution of flow types and the growth rate of AAAs. Lumen remodeling primarily occurs in region of recirculating blood flow with low velocities. However, the morphology of the lumen surface also appears to play a significant role. Notably, this finding pertains to the metric of lumen remodeling rather than intraluminal thickness.