Risk of aneurysmal rupture: The importance of neck orifice positioning - Assessment using computational flow simulation
Risk of aneurysmal rupture: The importance of neck orifice positioning - Assessment using computational flow simulation
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DOI：
10.1227/01.neu.0000297073.13423.3b
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发表时间：
2008-04-01
期刊：
影响因子：
4.8
通讯作者：
Yoshida, Jun
中科院分区：
文献类型：
--
作者：
Oshima, Tomotaka;Miyachi, Shigeru;Yoshida, Jun
目的：本研究的目的是澄清破裂的风险，在终端型颅内动脉瘤使用计算流模拟analysis.METHODS：首先，理想化的三维血管瘤模型建立从一个坚实的体素在计算机上。我们重点关注圆形终末型动脉瘤，根据与载瘤动脉轴相关的以下三种模式设置颈口定位：A型颈口定位与载瘤动脉血流直接一致; B型颈口向单侧分支偏移1.5 mm; C型颈口偏移3 mm。使用Fujitsu alpha-Flow软件（Fujitusu，Tokyo，Japan）进行计算流模拟。我们使用修改后的患者特异性模型分析了血流模式。结果：A型动脉瘤瘤颈口呈完全对称的流线型，C型动脉瘤颈口呈明显的圆形循环。另一方面，B型颈口表现出动脉瘤内血流分离。临床研究表明，破裂组中B型动脉瘤的发生率更高（P < 0.05）。结论：血流分离是内膜损伤的原因之一，但仅在B型动脉瘤中观察到，这一结果与我们的临床经验相符。从血流动力学的角度来看，颈口的这种定位可能是最有可能诱发未破裂动脉瘤破裂的风险因素之一。
OBJECTIVE: The aim of the present study was to clarify the risk of rupture in terminal-type intracranial aneurysms using computational flow simulation analysis.METHODS: First, idealized three-dimensional aneurysmal models were built from a solid voxel on the computer. We focused on round terminal-type aneurysms with the positioning of the neck orifice set according to the following three patterns in relationship to the axis of the parent artery: the Type-A neck orifice was positioned directly in line with the flow of the parent artery; the Type-B neck orifice was shifted 1.5 mm off line toward the unilateral branch; and the Type-C neck orifice was shifted 3 mm offline. Computational flow simulations were applied with Fujitsu alpha-Flow software (Fujitusu, Tokyo, Japan). We analyzed flow patterns using modified patient-specific models. We also investigated actual clinical situations to evaluate the differences in neck-orifice positioning between 20 ruptured aneurysms and 26 unruptured ones using three-dimensional angiograms.RESULTS: The Type-A neck orifice showed completely symmetrical stream lines in the aneurysm, whereas the Type-C orifice showed a clear round circulation. The Type-B neck orifice, on the other hand, exhibited intra-aneurysmal flow separation. The clinical research demonstrated that Type-B aneurysms were more likely to be found in the ruptured group (P < 0.05).CONCLUSION: Flow separation, recognized as one of the causes of intimal injury, could be observed only in Type-B aneurysms, a result that corresponded well with our clinical experience. From the flow-dynamics point of view, this positioning of the neck orifice may be one of the risk factors most likely to induce the rupture of unruptured aneurysms.