Retrograde embolism and atherosclerosis development in the human thoracic aorta: are the fluid dynamics explanations valid?

The mechanisms of atherosclerosis development in the thoracic aorta is misc ellaneous and still only partially understood. The marked variability of th e sites of deposition of atherosclerotic plaques in the aorta could not be clarified based solely on the risk-factors theory of atherosclerosis. The s ites of deposition of atherosclerotic plaques are considered to be affected by blood-flow patterns that cause areas of altered shear stress on the aor tic wall. Close relations between protruding aortic plaques (PAP), stroke a nd peripheral emboli were established. The analysis of PAP distribution and motion to characterize atherogenesis in the human thoracic aorta and the p athogeneses of embolic events was performed. We concluded that protruding a ortic plaques and markers of relative aortic flow instability (occurrences of vortices) are predominantly noticed in the human arch and in the descend ing aorta, whereas the ascending aorta showed lesser prevalence of atheroma tosis. Reversal and rotational blood-flow in the thoracic aorta most likely exist in all patients with systemic emboli and mobile protruding aortic at heromas. Therefore, retrograde cerebral embolism from distal aortic plaques is conceivable. (C) 2001 Harcourt Publishers Ltd.