School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287, USA.
IEEE Trans Biomed Eng. 2013 Apr;60(4):1150-9. doi: 10.1109/TBME.2012.2228002. Epub 2012 Nov 20.
Although coil embolization is one of the most effective treatments for intracranial aneurysms (ICAs), the procedure is often unsuccessful. For example, an ICA may persist after coil embolization if deployed coils fail to block the flow of blood into the aneurysm. Unfortunately, the specific flow changes that are effected by embolic coiling (and other endovascular therapies) are poorly understood, which creates a barrier to the design and execution of optimal treatments in the clinic. We present an in vitro pulsatile flow study of treated basilar tip aneurysm models that elucidates relationships between controllable treatment parameters and clinically important post-treatment fluid dynamics. We also compare fluid dynamic performance across embolic coils and more recently proposed devices (e.g., the Pipeline Embolization Device) that focus on treating ICAs by diverting rather than blocking blood flow. In agreement with previous steady flow studies, coil embolization-reduced velocity magnitude at the aneurysmal neck by greater percentages for a narrow-neck aneurysm, and reduced flow into aneurysms by greater percentages at lower parent vessel flow rates. However, flow diversion reduced flow into a wide-neck aneurysm more so than coil embolization, regardless of flow conditions. Finally, results also showed that for the endovascular devices we examined, treatment effects were generally less dramatic under physiologic pulsatile flow conditions as compared to steady flow conditions. The fluid dynamic performance data presented in this study represent the first direct in vitro comparison of coils and flow diverters in aneurysm models, and provide a novel, quantitative basis to aid in designing endovascular treatments toward specific fluid dynamic outcomes.
尽管线圈栓塞术是治疗颅内动脉瘤（ICAs）最有效的方法之一，但该手术通常并不成功。例如，如果部署的线圈未能阻止血液流入动脉瘤，那么 ICA 可能会在 coil embolization 后仍然存在。不幸的是，栓塞线圈（和其他血管内治疗）所引起的具体血流变化理解得很差，这为在临床中设计和执行最佳治疗方案设置了障碍。我们提出了一项关于治疗基底尖动脉瘤模型的脉动流体外研究，阐明了可控治疗参数与临床重要的治疗后流体动力学之间的关系。我们还比较了栓塞线圈和最近提出的设备（例如 Pipeline Embolization Device）之间的流体动力学性能，这些设备通过分流而不是阻断血流来专注于治疗 ICA。与之前的稳态流研究一致，对于狭窄颈动脉瘤，线圈栓塞术以更大的百分比降低了动脉瘤颈部的速度幅度，并且以更大的百分比降低了较低的母血管流量下的血流进入动脉瘤。然而，无论血流条件如何，血流分流都比 coil embolization 更能减少宽颈动脉瘤的血流。最后，结果还表明，对于我们研究的血管内设备，与稳态流条件相比，在生理脉动流条件下，治疗效果通常不那么显著。本研究中提出的流体动力学性能数据代表了在动脉瘤模型中首次对线圈和血流分流器进行的直接体外比较，并提供了一种新的、定量的基础，以帮助设计针对特定流体动力学结果的血管内治疗。
