Brunet J, Pierrat B, Adrien J, Maire E, Lane B A, Curt N, Bravin A, Laroche N, Badel P
Mines Saint-Étienne, Univ Jean Monnet, INSERM, U 1059 Sainbiose, 42023, Saint-Étienne, France; European Synchrotron Radiation Facility (ESRF), Grenoble, France; Department of Mechanical Engineering, University College London, London, UK.
Mines Saint-Étienne, Univ Jean Monnet, INSERM, U 1059 Sainbiose, 42023, Saint-Étienne, France.
Acta Biomater. 2023 Jan 1;155:449-460. doi: 10.1016/j.actbio.2022.10.060. Epub 2022 Nov 4.
Aortic dissection is a complex, intramural, and dynamic condition involving multiple mechanisms, hence, difficult to observe. In the present study, a controlled in vitro aortic dissection was performed using tension-inflation tests on notched rabbit aortic segments. The mechanical test was combined with conventional (cCT) and synchrotron (sCT) computed tomography for in situ imaging of the macro- and micro-structural morphological changes of the aortic wall during dissection. We demonstrate that the morphology of the notch and the aorta can be quantified in situ at different steps of the aortic dissection, and that the notch geometry correlates with the critical pressure. The phenomena prior to propagation of the notch are also described, for instance the presence of a bulge at the tip of the notch is identified, deforming the remaining wall. Finally, our method allows us to visualize for the first time the propagation of an aortic dissection in real-time with a resolution that has never previously been reached. STATEMENT OF SIGNIFICANCE: With the present study, we investigated the factors leading to the propagation of aortic dissection by reproducing this mechanical process in notched rabbit aortas. Synchrotron CT provided the first visualisation in real-time of an aortic dissection propagation with a resolution that has never previously been reached. The morphology of the intimal tear and aorta was quantified at different steps of the aortic dissection, demonstrating that the early notch geometry correlates with the critical pressure. This quantification is crucial for the development of better criteria identifying patients at risk. Phenomena prior to tear propagation were also described, such as the presence of a bulge at the tip of the notch, deforming the remaining wall.
主动脉夹层是一种复杂的、壁内的、动态的病症，涉及多种机制，因此难以观察。在本研究中，我们对有切口的兔主动脉段进行张力-充气试验，进行了体外控制的主动脉夹层实验。将力学测试与传统计算机断层扫描（cCT）和同步加速器计算机断层扫描（sCT）相结合，对主动脉夹层过程中主动脉壁的宏观和微观结构形态变化进行原位成像。我们证明，在主动脉夹层的不同阶段，可以对切口和主动脉的形态进行原位定量分析，并且切口几何形状与临界压力相关。还描述了切口扩展之前的现象，例如在切口尖端发现有凸起，使剩余的管壁变形。最后，我们的方法使我们首次能够以前所未有的分辨率实时观察主动脉夹层的扩展。重要性声明：通过本研究，我们通过在有切口的兔主动脉中重现这一力学过程，研究了导致主动脉夹层扩展的因素。同步加速器CT首次以从未达到过的分辨率实时显示了主动脉夹层的扩展。在主动脉夹层的不同阶段对内膜撕裂和主动脉的形态进行了定量分析，表明早期切口几何形状与临界压力相关。这种定量分析对于制定更好的标准来识别高危患者至关重要。还描述了撕裂扩展之前的现象，例如在切口尖端存在使剩余管壁变形的凸起。
