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Previous studies suggest that emboli are preferentially transported to larger branch arteries in excess of volumetric flow. This implies that cardiogenic emboli should be preferentially transported to the descending aorta; however, such emboli account for nearly 25% of ischemic strokes. We demonstrate for the first time the potential underlying mechanism for the predilection of cardiogenic embolic stroke.
Ten anatomically accurate computer models of the human aorta and arteries to the brain were derived from CT angiography. Blood flow was modeled by direct numerical simulation using a well–validated flow solver with pulsatile inflow and physiologic Windkessel models at the outlets. Particles ranging from 250 microns to 4 mm were injected at the aortic valve and tracked to the cerebral arteries.
The percentage of particles embolic to the brain increases significantly with particle size until a peak near 1 mm, and then decreases as particle size is increased further (Fig). On average, particles near 1mm in size are twice as likely to transverse the cerebral arteries than expectations based on volumetric flow. Only large particles (>3 mm) are preferentially transported to peripheral arteries.
Cardiogenic emboli less than 3 mm appear to have a strong size–dependent predilection for the cerebral arteries in excess of expectations based on flow distribution. The observed trend was consistent for all patient models analyzed, and robust to modeling assumptions.
Poster Sessions, Expo North
Saturday, March 09, 2013, 3:45 p.m.–4:30 p.m.
Session Title: Basic Science Underpinnings of Vascular Disease
Abstract Category: 33. Vascular Medicine: Basic
Presentation Number: 1166–163
- 2013 American College of Cardiology Foundation