The haemodynamics of asymmetric stenoses
The haemodynamics of asymmetric stenoses
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DOI：
10.1053/ejvs.2002.1729
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发表时间：
2002-10-01
影响因子：
5.7
通讯作者：
Dodds, SR
中科院分区：
文献类型：
--
作者：
Dodds, SR
目的：动脉闭塞性疾病通常是不规则的，有对称（同心）和不对称（偏心）狭窄。了解狭窄几何形状对狭窄血流动力学的影响对于正确解释从解剖学角度测量狭窄严重程度的测试是必要的。狭窄不对称的独立血流动力学影响尚未被描述。设计：使用血液模拟物（40%甘油）在6.7 mm直径的管中测量刚性、20mm长、方端对称和非对称狭窄的稳定压力/流动行为。结果：所有狭窄，无论几何形状，都具有线性流动阻力(R) (Q)关系，使得R = k(1) + k(2)Q，其中k(1)和k(2)是常数（相关性> 0.99,p < 0.05）。如果狭窄严重程度以直径缩小表示，则发现不对称对血流动力学有显著影响，但如果狭窄严重程度以面积缩小表示，则没有影响。当入流压力为90 mmHg （Q(90)）时，最大流量从2050下降到280 ml/min，狭窄面积减少从80%增加到96%。结论：无论其几何形状如何，动脉狭窄都表现出血流依赖性阻力。如果解剖严重性以面积减少百分比表示，狭窄不对称的影响只能被忽略。一个临床上有用的狭窄严重程度的测量是给定流入压力下的最大流量。
Objective: 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, 20 mm 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 = k(1) + k(2)Q where k(1) and k(2) are constants (corr > 0.99, p < 0.05). Asymmetry was found to have a significant haemodynamic effect if the stenosis severity is expressed as a diameter reduction but no effect if stenosis severity is expressed as an area reduction. The maximum flow for an inflow pressure of 90 mmHg (Q(90)) fell from 2050 to 280 ml/min as stenosis area reduction increased from 80% to 96%.Conclusions: Arterial stenoses exhibit flow-dependent resistance irrespective of their geometry. The effect of stenosis asymmetry can only be ignored if anatomical severity is expressed as a percentage area reduction. A clinically useful measure of stenosis severity is the maximum flow for a given inflow pressure.