It is commonly admitted that a dissection initiates with an intimal tear or at least a defect inside the arterial wall. Nevertheless, few studies investigated the initiation sequence due to the difficulty to monitor this process. The objective of this work was to observe and investigate the mechanisms leading an intimal tear to propagate into a dissection. A custom-made tension-inflation device fitting inside an X-ray microtomography setup was designed. A notch was created inside a porcine carotid artery before performing the tension-inflation test. The X-ray tomography setup allowed observing the wall-structure and the notch behavior during the inflation of the carotid artery. A quantitative description of the notch morphology was performed, suggesting the prevalence of high shear stress in the region of the crack tip as a possible trigger for propagation of a dissection. The present experimental approach allowed understanding better the mechanisms leading to dissection and constitutes a first step toward the improvement of failure modeling and risk assessment of this disease.

中文翻译：

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一种使用 X 射线显微断层扫描对加压动脉段进行体外 3D 成像的新方法

人们普遍认为，夹层始于内膜撕裂或至少是动脉壁内的缺损。然而，由于难以监测这一过程，很少有研究调查起始序列。这项工作的目的是观察和研究导致内膜撕裂传播到夹层的机制。设计了一种安装在 X 射线显微断层扫描装置内的定制张力膨胀装置。在进行张力膨胀测试之前，在猪颈动脉内创建了一个缺口。X 射线断层扫描设置允许在颈动脉膨胀期间观察壁结构和切口行为。对缺口形态进行了定量描述，表明裂纹尖端区域中高剪切应力的普遍存在是解剖传播的可能触发因素。目前的实验方法可以更好地理解导致解剖的机制，并构成了改进这种疾病的失败建模和风险评估的第一步。