Yu Liu, Xinmiao Zhang, Yawei Wang, Wentao Feng, Jing Jing, Zhunjun Sun, Bitian Wang, Yongjun Wang, Yubo Fan
Advanced Innovation Centre for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing University, Beijing 100083, China.
Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; China National Clinical Research Center for Neurological Diseases, Beijing, China.
Clin Biomech (Bristol). 2023 Jan;101:105853. doi: 10.1016/j.clinbiomech.2022.105853. Epub 2022 Dec 7.
Vertebrobasilar dolichoectasia is a rare cerebrovascular disease characterized by obvious extension, dilation and tortuosity of vertebrobasilar artery, and its pathophysiological mechanism is not clear. This study focused on local hemodynamic changes in basilar arteries with typical vertebrobasilar dolichoectasia, together with unbalanced vertebral arteries and abnormal structures of the circle of Willis, through multi-scale modeling.
Three-dimensional models of 3 types of vertebrobasilar arteries were constructed from magnetic resonance images. The first type has no vertebrobasilar dolichoectasia, the second type has vertebrobasilar dolichoectasia and balanced vertebral arteries, and the third type has vertebrobasilar dolichoectasia and unbalanced vertebral arteries. A lumped parameter model of the circle of Willis was established and coupled to these three-dimensional models.
The results showed that unbalanced bilateral vertebral arteries, especially single vertebral artery deletion mutation, might associate with higher wall shear stress on anterior wall of basilar artery in patients with vertebrobasilar dolichoectasia. And unbalanced bilateral vertebral arteries would increase the blood pressure in basilar artery. Meanwhile, missing communicating arteries in the circle of Willis, especially bilateral posterior communicating arteries absences, would significantly increase blood pressure in basilar artery. The unilateral absence of posterior communicating arteries would increase differences in blood flow between the left and right posterior cerebral arteries.
This study provided a multi-scale modeling method and some preliminary results for helping understand the role of hemodynamics in occurrence and development of vertebrobasilar dolichoectasia.
椎基底动脉延长扩张症是一种罕见的脑血管疾病，其特征为椎基底动脉明显延长、扩张及迂曲，其病理生理机制尚不清楚。本研究通过多尺度建模，聚焦于典型椎基底动脉延长扩张症患者基底动脉的局部血流动力学变化，以及椎动脉不对称和 Willis 环结构异常的情况。
从磁共振图像构建 3 种类型椎基底动脉的三维模型。第一类无椎基底动脉延长扩张症，第二类有椎基底动脉延长扩张症且椎动脉对称，第三类有椎基底动脉延长扩张症且椎动脉不对称。建立 Willis 环的集总参数模型，并将其与这三种三维模型耦合。
结果显示，双侧椎动脉不对称，尤其是单椎动脉缺失突变，可能与椎基底动脉延长扩张症患者基底动脉前壁较高的壁面切应力相关。而且双侧椎动脉不对称会增加基底动脉的血压。同时，Willis 环中交通动脉缺失，尤其是双侧后交通动脉缺如，会显著增加基底动脉血压。单侧后交通动脉缺如会增加左右大脑后动脉之间的血流差异。
本研究提供了一种多尺度建模方法和一些初步结果，有助于理解血流动力学在椎基底动脉延长扩张症发生发展中的作用。
