A novel combined fluid dynamic and strain analysis approach identified abdominal aortic aneurysm rupture

Figures

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  Fig 1. A, Three-dimensional geometry (outer wall and lumen) of the abdominal aortic aneurysm (AAA) under investigation. A patching system helped define 24 patches based on location (left, right, anterior, or posterior) and was employed to analyze region-averaged descriptors. The arrow indicates the site of rupture at the level of patch LP5. B, Left sagittal oblique view of cardiac gated computed tomography (CT) scan demonstrating periaortic fat stranding as early sign of contained rupture at the left posterolateral portion of aortic wall (circle). C, Axial view of cardiac gated CT scan showing location of rupture in evolution at around 5 o'clock on the clock face (circle).

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  Fig 2. Computational fluid dynamics (CFD)-predicted velocity contours on a longitudinal cross section of the abdominal aortic aneurysm (AAA) at different times of the cardiac cycle. From left: Systolic acceleration, systolic peak, systolic deceleration, diastole. It is possible to appreciate the presence of a main flow channel originating in the neck and characterized by higher velocities. Lower velocities and recirculation are present in the aneurysmal sac, especially at the level of the rupture site. The shade of both lumen and wall geometry is shown.

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  Fig 3. Top, Distribution of time-averaged wall shear stress (TAWSS) on luminal surface, intraluminal thrombus (ILT) thickness on wall surface, and maximum principal strain on wall surface. The outline of the patches is visible on top of the distribution. Bottom, Distribution of region-averaged TAWSS on luminal surface, region-averaged ILT thickness on wall surface, and region-averaged maximum principal strain on wall surface.

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  Fig 4. Regional Rupture Potential (RRP) index computed on patches on the aortic wall surface. The arrow indicates the site of rupture at the level of patch LP5.