Computational Fluid Dynamics Modeling of Proximal Landing Zones for Thoracic Endovascular Aortic Repair in the Bovine Arch Variant

Abstract Purpose To assess the endograft displacement forces (DF), which quantify the forces exerted by the pulsatile blood flow on the vessel wall and transmitted on the terminal fixation site of the endograft after its deployment, in proximal landing zones (PLZs) of the bovine aortic arch variant. Methods Thirty healthy aortic CT angiographies of subjects with bovine arch configuration (10 per Type of arch, I to III) were selected for the purpose of the study. A 3D model of the aortic arch lumen was reconstructed. Computational fluid dynamics modelling was then employed to compute DF magnitude and orientation (i.e. x,y,z axes) in PLZs of each case. DF values were normalised to the corresponding aortic wall area to estimate equivalent surface traction (EST). Results DF were highest in Zone 0, consistently with the greater surface area. DF in Zone 3 were much greater than in Zone 2 due to a three-fold greater upward component (z-axis) (P Conclusions The bovine arch is associated with a consistent fluid dynamic pattern, which identifies in Zone 3 an unfavorable biomechanical environment for endograft deployment.