Cebral Juan R, Mut Fernando, Lohner Rainald, Abdurakhmonov Mukhayyirkhuja, Ramezanpour Mehdi, Tobe Yasutake, Robertson Anne M
Bioengineering Department, George Mason University, Fairfax, Virginia, USA.
Physics Department, George Mason University, Fairfax, Virginia, USA.
Int J Numer Method Biomed Eng. 2025 Jun;41(6):e70051. doi: 10.1002/cnm.70051.
The role of the vasa vasorum in the growth and rupture of intracranial aneurysms, as well as the conditions stimulating its local development along aneurysm walls are not completely clear and have not been studied on an aneurysm-specific basis. In this study, the oxygen distribution throughout the wall of an intracranial aneurysm that underwent substantial thickening and developed an extensive adventitial vasa vasorum network was numerically modeled in order to elucidate the role played by the vasa vasorum. The computational model was constructed based on high-resolution ex vivo micro computed tomography and multi-photon microscopy images of a tissue sample of the aneurysm harvested during open surgery. The mathematical model was based on the transport equation including oxygen diffusion and consumption in the tissue and diffusion across the lumen in the intimal side, and the vasa vasorum in the adventitial side. The governing equation was numerically solved with a finite volume approach on a high-resolution mesh containing approximately 48 million tetrahedra with an element size of 10 μm. The results demonstrate that the observed vasa vasorum plexus provided adequate oxygen supply to the outer layers of the thickened walls. Furthermore, the models show that without the vasa vasorum, due to consumption throughout the wall, the oxygen demand could not be met by diffusion from the luminal surface. These findings support the idea that local hypoxic conditions in regions of increased wall thickness stimulate the development of the vasa vasorum network on the adventitial surface.
血管滋养管在颅内动脉瘤生长和破裂中的作用，以及刺激其沿动脉瘤壁局部发育的条件尚不完全清楚，且尚未在特定动脉瘤基础上进行研究。在本研究中，对一个经历了显著增厚并形成广泛外膜血管滋养管网的颅内动脉瘤壁的氧分布进行了数值模拟，以阐明血管滋养管所起的作用。该计算模型是基于高分辨率离体微型计算机断层扫描和在开颅手术期间采集的动脉瘤组织样本的多光子显微镜图像构建的。数学模型基于包括组织中氧扩散和消耗以及在内膜侧跨管腔扩散和在外膜侧血管滋养管扩散的输运方程。控制方程在一个包含约4800万个四面体且单元尺寸为10μm的高分辨率网格上用有限体积法进行数值求解。结果表明，观察到的血管滋养管丛为增厚壁的外层提供了充足的氧气供应。此外，模型显示，若无血管滋养管，由于整个壁的消耗，从管腔表面扩散无法满足氧需求。这些发现支持这样一种观点，即壁厚增加区域的局部缺氧状况刺激了外膜表面血管滋养管网的发育。
