不同破口大小和位置的斯坦福A型主动脉夹层风险：一项数值研究
The risk of stanford type-A aortic dissection with different tear size and location: a numerical study.
作者信息
Shi Yue, Zhu Minjia, Chang Yu, Qiao Huanyu, Liu Yongmin
机构信息
School of Life Science and BioEngineering, Beijing University of Technology, Beijing, 100124, People's Republic of China.
Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, People's Republic of China.
出版信息
Biomed Eng Online. 2016 Dec 28;15(Suppl 2):128. doi: 10.1186/s12938-016-0258-y.
BACKGROUND
This study is to investigate the influence of hemodynamics on Stanford type-A aortic dissection with different tear size and location, to provide some support for the relationships between the risks (rupture, reverse tearing and further tearing) and tear size and location for clinical treatment.
METHODS
Four numerical models of Stanford type-A aortic dissection were established, with different size and location of the tears. The ratio of the area between the entry and re-entry tears(RA) is various within the model; while, the size and the location of the re-entry in the distal descending aorta are fixed. In model A11 and A21, the entry tears are located near the ascending aorta. The RA in these models are 1 and 2, respectively; In the model B11 and B21, the entry tears are located near the proximal descending aorta and the RA in these models are again assigned to 1 and 2, respectively. Then hemodynamics in these models was solved with numerically and the flow patterns and loading distributions were investigated.
RESULTS
The flow velocity of the true lumen in model A21, B21 is lower than that in A11, B11, respectively; the time-averaged wall shear stress (TAWSS) of the false lumen in model A21 and B21 is higher, and for ascending aorta false lumen, A11, A21 are higher than B11, B21, respectively. False lumen intimal wall pressure of A11, A21 are always higher than the true lumen ones.
CONCLUSION
The variation of the RA can significantly affect the dynamics of blood within the aortic dissection. When the entry tear size is larger than the re-entry tear ones, the false lumen, proximal descending aorta and the wall near re-entry tear are prone to cracking. Entry tear location can significantly alter the hemodynamics of aortic dissection as well. When entry tear location is closer to proximal ascending aorta, false lumen continues to expand and compress the true lumen resulting in the true lumen reduction. For proximal ascending aorta, high pressure in false lumen predicts a higher risk of reverse tear.
背景
本研究旨在探讨血流动力学对不同破口大小和位置的 Stanford A 型主动脉夹层的影响，为临床治疗中风险（破裂、逆向撕裂和进一步撕裂）与破口大小和位置之间的关系提供一定支持。
方法
建立了四个 Stanford A 型主动脉夹层的数值模型，破口大小和位置各不相同。模型中入口与再入口破口之间的面积比（RA）各不相同；而远端降主动脉再入口的大小和位置是固定的。在模型 A11 和 A21 中，入口破口位于升主动脉附近。这些模型中的 RA 分别为 1 和 2；在模型 B11 和 B21 中，入口破口位于近端降主动脉附近，这些模型中的 RA 也分别设定为 1 和 2。然后对这些模型的血流动力学进行数值求解，并研究血流模式和载荷分布。
结果
模型 A21、B21 中真腔的流速分别低于 A11、B11 中的流速；模型 A21 和 B21 中假腔的时间平均壁面切应力（TAWSS）较高，对于升主动脉假腔，A11、A21 分别高于 B11、B21。A11、A21 的假腔内内膜壁压力始终高于真腔。
结论
RA 的变化可显著影响主动脉夹层内的血液动力学。当入口破口尺寸大于再入口破口时，假腔、近端降主动脉和再入口破口附近的壁更容易破裂。入口破口位置也可显著改变主动脉夹层的血流动力学。当入口破口位置更靠近近端升主动脉时，假腔持续扩张并压缩真腔，导致真腔缩小。对于近端升主动脉，假腔内的高压预示着逆向撕裂的风险更高。
Zotero 插件