Introduction: Ischemic strokes account for 87% of all strokes, >50% of which are cardio-embolic and cryptogenic in origin. Current embolic protection devices include permanent left atrial appendage occlusion and temporary aortic arch and carotid filtration systems, none of which maintain an open-channel orientation.
Hypothesis: A novel cardio-embolic protection device is theorized to shift embolic particle trajectory away from cranial vessels while maintaining an open-channel orientation. In this study, we constructed a 4-dimensional (4D) computational fluid dynamics (CFD) model to track aortic arch blood flow patterns and cardio-embolic particle trajectory in a computerized human aorta model, before and after virtual deployment of a computer-aided design (CAD) device prototype.
Methods: Native 4D aortic arch flow patterns were modeled independently. Spherical particles of uniform density and variable diameter were introduced to track embolic patterns. A CAD model of the embolic protection device (an intravascular contoured surface) was positioned at the greater curvature of the ascending aorta immediately proximal to the brachiocephalic artery origin. All simulations were repeated to reassess device-modulated flow dynamics and particle trajectory. Constant blood fluid density, particle density, pulsatile aortic flow velocity profile, and aortic wall geometries were prescribed for uniform comparison.
Results: Embolic particle trajectory to individual cranial vessels (BCA, LCCA, LSCA) after device implantation reduced by 40.2%, 23.8%, and 22.6% respectively (mean 28.9%). Particles sized 5 mm - 9 mm and those sized 9 mm yielded 39.4% and 47.6% mean embolic event reduction respectively.
Conclusions: Pre-clinical CFD simulations support the cardio-embolic particle-deflective properties of a novel implantable device yielding 39.4% and 47.6% mean embolic reduction for 5-9 mm particles and 9 mm respectively (mean 28.9% for all particle sizes). The greatest protective effect was noted at the BCA, followed by LCCA and LSCA. Further simulations of related device embodiments are warranted as pre-clinical validation of this potential stroke protection strategy.
