Saccular Aneurysms on Straight and Curved Vessels Are Subject to Different Hemodynamics: Implications of Intravascular Stenting

Inflow momentum as a function of vessel curvature (zero curvature corresponds to the sidewall aneurysm) from CFD simulation (Re = 128). Inflow momentum is calculated at the interface between the aneurysm orifice and parent vessel. The values for both untreated and stented models are calculated, but only the untreated models are labeled with values to show the difference between the straight vessel model (S) and the curved vessel (C) models.

CFD simulation (3D) of aneurysmal flow in the straight vessel model (S) and one of the curved vessel models (C3) (Re = 128). Plotted are 2-dimensional velocity fields in the center plane. Insert reveals flow sieving through the stent struts in the straight vessel model. Shown is the vertical velocity magnitude contour at the aneurysm–parent vessel interface.

Dye visualization of the straight vessel model (S) and one of the curved vessel models (C3). The pictures are selected from the third image after the first appearance of dye in the aneurysm sac to represent the wash-in status.

SI before and after stent placement as a function of vessel curvature for each model (S, straight; C, curved vessel) in the dye visualization experiment. As the curvature increases, SI decreases. Stent placement increases SI, but the increment is smaller in larger curvature models.

WSS distribution at the distal aneurysm wall and distal vessel wall in straight (S) and curved (C) models before and after stent placement, calculated from CFD simulation (Re = 490). Color scale represents WSS values from <15 dynes/cm² (deep blue) to >35 dynes/cm² (bright red). The impact zone is defined as the area where WSS is >20 dyne/cm², a value considered the upper limit for normal physiologic WSS.