Tanweer Omar, Wilson Taylor A, Metaxa Eleni, Riina Howard A, Meng Hui
Department of Neurosurgery, New York University School of Medicine, NY, United States.
Foundation for Research and Technology - Hellas Institute of Applied and Computational Mathematics, Crete, Greece.
J Cerebrovasc Endovasc Neurosurg. 2014 Dec;16(4):335-49. doi: 10.7461/jcen.2014.16.4.335. Epub 2014 Dec 30.
Cerebral aneurysms (CAs) and abdominal aortic aneurysms (AAAs) are degenerative vascular pathologies that manifest as abnormal dilations of the arterial wall. They arise with different morphologies in different types of blood vessels under different hemodynamic conditions. Although treated as different pathologies, we examine common pathways in their hemodynamic pathogenesis in order to elucidate mechanisms of formation.
A systematic review of the literature was performed. Current concepts on pathogenesis and hemodynamics were collected and compared.
CAs arise as saccular dilations on the cerebral arteries of the circle of Willis under high blood flow, high wall shear stress (WSS), and high wall shear stress gradient (WSSG) conditions. AAAs arise as fusiform dilations on the infrarenal aorta under low blood flow, low, oscillating WSS, and high WSSG conditions. While at opposite ends of the WSS spectrum, they share high WSSG, a critical factor in arterial remodeling. This alone may not be enough to initiate aneurysm formation, but may ignite a cascade of downstream events that leads to aneurysm development. Despite differences in morphology and the structure, CAs and AAAs share many histopathological and biomechanical characteristics. Endothelial cell damage, loss of elastin, and smooth muscle cell loss are universal findings in CAs and AAAs. Increased matrix metalloproteinases and other proteinases, reactive oxygen species, and inflammation also contribute to the pathogenesis of both aneurysms.
Our review revealed similar pathways in seemingly different pathologies. We also highlight the need for cross-disciplinary studies to aid in finding similarities between pathologies.
脑动脉瘤(CAs)和腹主动脉瘤(AAAs)是退行性血管病变,表现为动脉壁异常扩张。它们在不同的血流动力学条件下,于不同类型的血管中呈现出不同的形态。尽管被视为不同的病变,但我们研究它们血流动力学发病机制中的共同途径,以阐明其形成机制。
对文献进行系统综述。收集并比较当前关于发病机制和血流动力学的概念。
脑动脉瘤在高血流、高壁面切应力(WSS)和高壁面切应力梯度(WSSG)条件下,在Willis环的脑动脉上以囊状扩张形式出现。腹主动脉瘤在低血流、低且振荡的WSS以及高WSSG条件下,在肾下腹主动脉上以梭形扩张形式出现。虽然它们处于WSS谱的两端,但都具有高WSSG,这是动脉重塑的关键因素。这本身可能不足以引发动脉瘤形成,但可能引发一系列导致动脉瘤发展的下游事件。尽管在形态和结构上存在差异,但脑动脉瘤和腹主动脉瘤具有许多组织病理学和生物力学特征。内皮细胞损伤、弹性蛋白丢失和平滑肌细胞丢失是脑动脉瘤和腹主动脉瘤的普遍表现。基质金属蛋白酶和其他蛋白酶、活性氧和炎症增加也有助于两种动脉瘤的发病机制。
我们的综述揭示了看似不同的病变中存在相似的途径。我们还强调了跨学科研究对于帮助发现病变之间相似性的必要性。