Atherosclerotic plaques in human coronary arteries localized almost exclusively at sites of slow or disturbed flow and low wall shear stress, such as the outer wall of bifurcations.
Observational (n=5)
To investigate the potential role of fluid mechanical factors in the localized genesis and development of atherosclerotic lesions in humans, the exact anatomic locations of atherosclerotic lesions and the flow patterns at such sites in left and right human coronary arteries were studied in detail by flow visualization and high-speed cinemicrographic techniques using five isolated, transparent human coronary arterial trees prepared postmortem. It was found that atherosclerotic plaques and wall thickenings in left and right coronary arteries were localized almost exclusively on the outer wall of one or both daughter vessels at major bifurcations and T-junctions, which left the flow-divider free of lesions, and along the inner wall of curved segments. When flow patterns in such vessels were studied in detail, it was discovered that these sites were where flow was either slow or disturbed with the formation of slow recirculation and secondary flows and where wall shear stress was low. The results indicate that the major hemodynamic factors directly related to the localization of atherosclerotic plaques and wall thickenings in the human arterial system are the low fluid velocity and the resultant low shear stress that acts on the vessel wall.
Asakura et al. (1990) conducted an observational in Atherosclerotic lesions in human coronary arteries (n=5). Flow visualization and high-speed cinemicrographic techniques was evaluated on Anatomic locations of atherosclerotic lesions and flow patterns at such sites. Atherosclerotic plaques in human coronary arteries localized almost exclusively at sites of slow or disturbed flow and low wall shear stress, such as the outer wall of bifurcations.