The Haemodynamics of Asymmetric Stenoses

AbstractObjective: Occlusive arterial disease is usually irregular with both symmetric (concentric) and asymmetric (eccentric) stenoses. Knowledge of the effect of stenosis geometry on stenosis haemodynamics is necessary to correctly interpret tests that measure stenosis severity anatomically. The independent haemodynamic effect of stenosis asymmetry has not been described.Design: In vitro flow-rig measurement of the steady pressure/flow behaviour of rigid, 20mm long, square-ended symmetric and asymmetric stenoses in a 6.7-mm diameter tube using a blood analogue (40% glycerol).Results: All stenoses, irrespective of geometry, had a linear resistance (R) to flow (Q) relationship such that R=k1+ k2Q where k1 and k2 are constants (corr>0.99, p