A Novel Method for In Vitro 3D Imaging of Dissecting Pressurized Arterial Segments Using X-Ray Microtomography

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.