肾动脉粥样硬化斑块特征与血流动力学的关系及其对肾功能的影响

The relationship of hemodynamics with plaque characteristics and renal function of the stenotic renal artery based on computational fluid dynamics

目的:探讨血流动力学指标和肾动脉粥样硬化斑块特征之间的关系,及其在预测肾功能受损方面的效能。方法:回顾性分析2021年11月—2023年5月单侧肾动脉中重度狭窄患者的肾动脉CTA图像,评估肾动脉斑块特征(狭窄程度、斑块最大厚度、斑块面积、斑块体积、斑块负荷、动脉重塑和钙化)及肾皮质厚度差值(Cortical thickness difference,CTD)。使用有限元软件评估血流动力学参数时间平均壁剪切力(Time-averaged wall shear stress,TAWSS)及跨病变壁剪切力比(Wall shear stress ratio,WSSR)。测量并比较不同WSSR组间斑块特征的差异,并分析其与斑块特征的相关性。采用Logistic回归分析评价影响肾皮质厚度的独立危险因素。结果:最终纳入104例患者。狭窄处TAWSS高于狭窄前TAWSS和狭窄后TAWSS(P均<0.001),狭窄前TAWSS高于狭窄后TAWSS(P<0.001)。高WSSR组的狭窄程度、斑块负荷、非钙化斑块比例均高于低WSSR组(P=0.019、P=0.008、P=0.011)。WSSR与狭窄程度(r=0.028,P=0.020)和斑块负荷(r=0.028,P=0.020)呈正相关。斑块负荷(OR=1.764;95%CI 1.008~8.087;P=0.047)和高WSSR(OR=3.047;95%CI 1.123~8.262;P=0.029)是与高CTD独立相关的影像学因素。二者联合预测高CTD的AUC为0.72。结论:WSSR和斑块特征可能是肾动脉狭窄后反映肾功能指标的重要参数,斑块负荷和高WSSR可以预测肾功能的受损程度。

Objective:We aimed to investigate the relationship between computational fluid dynamics metric and anatomical and morphological features of renal artery stenosis,and their efficacy in predicting impaired renal function.Methods:Renal artery CTA images of renal arteries in patients with moderate-to-severe unilateral renal atherosclerotic plaque from November 2021 to May 2023 were retrospectively analyzed to evaluaterenal artery plaque characteristics(degree of stenosis,maximum plaque thickness,plaque area,plaque volume,plaque burden,arterial remodeling and calcification)and cortical thickness difference(CTD).Hemodynamic parameters including time-averaged wall shear stress(TAWSS)and wall shear stress ratio(WSSR)across the lesion were evaluated by finite element software.Differences in plaque characteristics among different WSSR groups were compared,and the correlation with plaque characteristics was analyzed.Logistic regression analysis was used to evaluate independent risk factors for renal cortical thickness.Results:A total of 104 patients were included in the analysis.TAWSS in stenosis was higher than that in pre-stenotic and post-stenotic areas(P<0.001),and pre-stenotic TAWSS was higher than post-stenotic TAWSS(P<0.001).The stenosis severity,plaque burden and proportion of non-calcified plaque in the high WSSR group were higher than those in the low WSSR group(P=0.019,P=0.008,P=0.011).WSSR was positively correlated with stenosis severity(r=0.028,P=0.02)and plaque burden(r=0.028,P=0.02).Plaque burden(OR 1.764;95%CI 1.008~8.087;P=0.047)and high WSSR(OR 3.047;95%CI 1.123~8.262;P=0.029)were independently associated with high CTD.The AUC of high CDT predicted by the combination of the two parameters is 0.72.Conclusion:WSSR and plaque characteristics may provide important parameters to reflect renal function after renal artery stenosis.Plaque burden and high WSSR can predict the degree of renal function impairment.