Velocity field studies at surgically imposed arterial stenoses on the abdominal aorta in pigs
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Velocity field studies at surgically imposed arterial stenoses on the abdominal aorta in pigs. / Hjortdal, J O; Pedersen, E M; Hjortdal, V E; Hasenkam, J M; Nygaard, H; Kim, Y W; Paulsen, P K.
In: Journal of Biomechanics, Vol. 24, No. 12, 1991, p. 1081-93.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Velocity field studies at surgically imposed arterial stenoses on the abdominal aorta in pigs
AU - Hjortdal, J O
AU - Pedersen, E M
AU - Hjortdal, V E
AU - Hasenkam, J M
AU - Nygaard, H
AU - Kim, Y W
AU - Paulsen, P K
PY - 1991
Y1 - 1991
N2 - In order to describe velocity profiles and the size of deterministic and non-deterministic velocity disturbances at arterial stenoses, symmetrical and asymmetrical stenoses with intended area reductions of 50% ('moderate') and 85% ('severe') were applied on the abdominal aorta in six pigs. Blood velocities were registered by hot-film anemometry in 21 measuring points distributed across the vessel cross-sectional area in one pre-stenotic and three post-stenotic positions. Signal analysis included ensemble averaging, the high-pass filtering technique, and three-dimensional visualization. None of the stenoses affected the pre-stenotic velocity field. Downstream moderate stenoses flow separation and vortex formation were present. Moderate asymmetric stenoses induced turbulence in the post-stenotic velocity field. Immediately downstream of severe stenoses a prominent post-stenotic jet was present. Farther downstream, a multitude of coherent vortices and turbulence dominated the flow field. The transverse distribution of turbulence intensity paralleled with the peak systolic velocity profile, whereas transverse profiles of the relative turbulence intensity (turbulence intensity/mean velocity) revealed peak values in flow field locations with high velocity gradients. Velocity parameters for symmetric and asymmetric severe stenoses were highly comparable. However, the exact degree of stenosis was significantly higher for symmetrical (85%) than for asymmetrical (76%) stenoses. Therefore, recalling that stenosis severity strongly influences the development of velocity disturbances, this indicates that asymmetry of a stenosis is a predictor for blood velocity disturbances.
AB - In order to describe velocity profiles and the size of deterministic and non-deterministic velocity disturbances at arterial stenoses, symmetrical and asymmetrical stenoses with intended area reductions of 50% ('moderate') and 85% ('severe') were applied on the abdominal aorta in six pigs. Blood velocities were registered by hot-film anemometry in 21 measuring points distributed across the vessel cross-sectional area in one pre-stenotic and three post-stenotic positions. Signal analysis included ensemble averaging, the high-pass filtering technique, and three-dimensional visualization. None of the stenoses affected the pre-stenotic velocity field. Downstream moderate stenoses flow separation and vortex formation were present. Moderate asymmetric stenoses induced turbulence in the post-stenotic velocity field. Immediately downstream of severe stenoses a prominent post-stenotic jet was present. Farther downstream, a multitude of coherent vortices and turbulence dominated the flow field. The transverse distribution of turbulence intensity paralleled with the peak systolic velocity profile, whereas transverse profiles of the relative turbulence intensity (turbulence intensity/mean velocity) revealed peak values in flow field locations with high velocity gradients. Velocity parameters for symmetric and asymmetric severe stenoses were highly comparable. However, the exact degree of stenosis was significantly higher for symmetrical (85%) than for asymmetrical (76%) stenoses. Therefore, recalling that stenosis severity strongly influences the development of velocity disturbances, this indicates that asymmetry of a stenosis is a predictor for blood velocity disturbances.
KW - Animals
KW - Aorta, Abdominal/pathology
KW - Aortic Valve Stenosis/pathology
KW - Blood Flow Velocity/physiology
KW - Blood Pressure
KW - Female
KW - Heart Rate
KW - Hematocrit
KW - Regional Blood Flow/physiology
KW - Rheology
KW - Swine
U2 - 10.1016/0021-9290(91)90001-4
DO - 10.1016/0021-9290(91)90001-4
M3 - Journal article
C2 - 1837551
VL - 24
SP - 1081
EP - 1093
JO - Journal of Biomechanics
JF - Journal of Biomechanics
SN - 0021-9290
IS - 12
ER -
ID: 244328679