Department of Interventional Neuroradiology, Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Tiantan Xili 6, Chongwen District, Beijing 100050, China.
Stroke. 2011 Mar;42(3):745-53. doi: 10.1161/STROKEAHA.110.593517. Epub 2011 Jan 13.
Hemodynamic factors are thought to play an important role in the initiation, growth, and rupture of cerebral aneurysms. However, the hemodynamic features in the residual neck of the partially embolized aneurysms and their influences on recanalization are rarely reported. In this study, we characterized the hemodynamics of partially occluded aneurysms, which were proven to undergo recanalization during follow-up using computational fluid dynamic analysis.
From May 2007 to June 2009, we identified 11 partial aneurysms during follow-up, including 5 recanalized cases and 6 stable cases with 3-dimensional digital subtraction angiography. We retrospectively characterized the hemodynamic features around the residual aneurysmal pouch using the available postprocedural digital subtraction angiography image data. The occluded part of the aneurysm was regarded as completely separated from the circulation.
The overall blood flow patterns before embolization were almost the same in the recanalized and stable groups. After occlusion, the flow pattern changes, wall shear stress (WSS), and velocity at the remnant neck demonstrated different changes between the 2 groups. Specifically, in the recanalized group, high WSS regions were found near the neck in all 5 cases, with 4 of them being even higher than those before occlusion. Interestingly, in all cases, the high WSS area of the remnant neck coincided with the location where the aneurysm recanalization occurred. In the stable group, 5 out of 6 cases demonstrated lower WSS and velocity at the remnant neck after occlusion.
High WSS and blood flow velocity were consistently observed near the remnant neck of partially embolized aneurysms prone to future recanalization, suggesting that hemodynamic factors may have an important role in aneurysmal recurrence after endovascular treatment. The difference in flow pattern could be caused by the incomplete occlusion of the aneurysms.
血流动力学因素被认为在脑动脉瘤的起始、生长和破裂中起着重要作用。然而，部分栓塞的动脉瘤残颈中的血流动力学特征及其对再通的影响很少有报道。在这项研究中，我们使用计算流体动力学分析来描述部分闭塞的动脉瘤的血流动力学特征，这些动脉瘤在随访期间被证实发生了再通。
2007 年 5 月至 2009 年 6 月，我们通过三维数字减影血管造影（3D-DSA）在随访中发现了 11 个部分动脉瘤，其中 5 个为再通病例，6 个为稳定病例。我们回顾性地描述了残留的动脉瘤囊周围的血流动力学特征，这些特征可通过可用的术后 3D-DSA 图像数据获得。动脉瘤的闭塞部分被认为与循环完全分离。
再通组和稳定组在栓塞前的整体血流模式几乎相同。栓塞后，血流模式发生变化，残余颈部的壁面切应力（WSS）和速度在两组之间表现出不同的变化。具体而言，在再通组的 5 例中，在颈部附近都发现了高 WSS 区域，其中 4 例甚至高于栓塞前的水平。有趣的是，在所有病例中，残余颈部的高 WSS 区域与动脉瘤再通的位置一致。在稳定组中，栓塞后 6 例中有 5 例残余颈部的 WSS 和速度较低。
在部分栓塞的动脉瘤的残余颈部附近，始终观察到高 WSS 和血流速度，这表明血流动力学因素可能在血管内治疗后动脉瘤复发中起着重要作用。血流模式的差异可能是由于动脉瘤不完全闭塞所致。
