Aarhus University Hospital Skejby, MR-Center, Brendstrupgaardsvej 100, DK-8200, Aarhus N, Denmark.
Stroke. 2010 May;41(5):1041-3. doi: 10.1161/STROKEAHA.109.571588. Epub 2010 Mar 11.
Mechanical stress may contribute to plaque rupture in patients with carotid atherosclerosis. We determined longitudinal mechanical stresses in carotid atherosclerotic plaques and compared them with known markers of plaque vulnerability.
Nineteen symptomatic patients scheduled for carotid endarterectomy underwent carotid MRI with a multicontrast protocol to characterize plaque morphology and geometry. Longitudinal 2-dimensional computational models were generated from the MRI data, and the mechanical stresses were calculated.
Peak longitudinal mechanical stresses occurred predominantly in the shoulder regions of the carotid plaque and correlated inversely with fibrous cap thickness (r(s)=-0.61; P=0.01), and increasing degrees of stenosis (r(s)=0.71; P=0.003). Peak stress levels were asymmetrically distributed longitudinally, with 50% occurring proximal to the maximal stenosis, 25% at the point of maximal stenosis, and 25% distal to the maximal stenosis.
The peak longitudinal mechanical stresses in the fibrous caps of symptomatic patients with carotid atherosclerotic stenosis were located at known predilection sites for plaque rupture, suggesting that mechanical stresses may play a role in plaque destabilization.
机械应力可能导致颈动脉粥样硬化患者斑块破裂。我们确定了颈动脉粥样硬化斑块中的纵向机械应力，并将其与已知的斑块易损性标志物进行了比较。
19 例有症状的颈动脉粥样硬化患者接受颈动脉 MRI 检查，采用多对比协议对斑块形态和几何结构进行特征描述。从 MRI 数据生成二维计算模型，并计算机械应力。
纵向峰值机械应力主要发生在颈动脉斑块的肩部区域，与纤维帽厚度呈负相关（r(s)=-0.61；P=0.01），与狭窄程度的增加呈正相关（r(s)=0.71；P=0.003）。峰值应力水平在纵向呈不对称分布，50%发生在最大狭窄近端，25%发生在最大狭窄处，25%发生在最大狭窄远端。
颈动脉粥样硬化狭窄症状患者纤维帽中的纵向峰值机械应力位于已知的斑块破裂易患部位，提示机械应力可能在斑块失稳中起作用。
