Abstract 19053: Embolic Particles Show Surprising Size Dependent Predilection for Cerebral versus Peripheral Arteries: Results from Computational Fluid Dynamic Modeling
Background: Embolic particles originating at the aortic valve or ascending aorta can have devastating consequences if they enter the cerebral circulation. Little is known about anatomic embolic origin and cerebral events, as this relationship is difficult to observe. To better understand emboli arising from procedures such as TAVR, we built a computational fluid dynamic (CFD) model of cerebral emboli originating at the aortic valve and ascending aorta.
Methods: An exact computer model of a human aorta and arteries to the brain was derived from CT angiography. Blood flow was modeled by the Navier-Stokes equations using pulsatile inflow at the inlet and physiologic Windkessel models at the outlets. Embolic particulate was injected at the level of the aortic valve and tracked using modified Maxey-Riley equations.
Results: Aortic emboli that entered the cerebral circulation through the carotid or vertebral arteries were localized to specific locations of the proximal aorta, most closely in the region of the right and non-coronary aortic valve cusps. The percent of released particles embolic to the brain was markedly dependent on particle size. Particles 1.0 mm diameter had a 28% chance of reaching the brain, whereas particles 2.5 mm dia or greater had 5% chance of reaching the brain.
Conclusions: Embolic particles reaching the brain appear have specific anatomic locations of origin, and may exhibit a strong size-destination relationship, with larger particulate (greater than 2.5 mm dia) less likely to traverse the cerebral vessel by a factor of 5 or greater. Particles less than 2 mm dia and originating from the right and noncoronary cusps appear more likely to cause cerebral injury according to this model. These data are consistent with sparse literature based on transesophageal echo observations. This CFD modeling method may prove useful for limiting aortic emboli to the brain during cardiovascular procedures.
- © 2012 by American Heart Association, Inc.