Alteration in fluid mechanics in femoral arteries with atheroma development

The relationship between regional alterations in wall motion, normalized wall shear amplitude (NWSA), and atheromatic lesion composition was evaluated in the Yucatan miniswine model with developing atherosclerosis. We induced vascular lesions by endothelial cell denudation. The animals were fed a high cholesterol diet for 8 weeks to develop early atherosclerotic lesions. At the end of the 8 weeks, hemodynamic and intravascular ultrasound (IVUS) image data were obtained in both the denuded and control femoral arteries. The vascular segment geometry was reconstructed from the imaging data and the CFD analysis performed in each segment incorporating the vascular wall motion data obtained from the images as a moving boundary condition. NWSA was correlated with vessel wall motion and lesion composition. Data from 6 control and 4 diseased arteries were analyzed. Results demonstrate that wall motion and NWSA increased in an arterial segment with atheroma compared to those in healthy regions, as determined from histology. However, the wall motion in the diseased segments demonstrated regional variability compared to relatively uniform distribution in the healthy segments. This study demonstrates the regional variability in the wall motion and NWSA in vascular segments in the presence of early atheroma compared to those in healthy segments.