Dennis Kendall D, Rossman Timothy L, Kallmes David F, Dragomir-Daescu Dan
Division of Engineering, Mayo Clinic, Rochester, Minnesota, USA.
Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota, USA.
J Neurointerv Surg. 2015 Dec;7(12):937-42. doi: 10.1136/neurintsurg-2014-011323. Epub 2014 Oct 3.
Limitations on treating large, giant, and wide-necked aneurysms with coiling have made flow diverters a promising alternative to current practice by supporting reconstruction of the parent artery.
To assess the changes to fluid dynamics within an aneurysm by studying two different endoluminal flow diverters on a simple aneurysm model, using tomographic particle image velocimetry to determine which device would better minimize fluid flow into an aneurysm and observe any significant changes in aneurysm fluid structures.
Steady velocity fields of the model's aneurysm dome and neck were measured at three inlet velocities (18, 39, and 59 cm/s) for two flow diverter diameters with different porosities and compared against a baseline case with no flow diverter.
In the baseline case a large vortex was present inside the dome for all flow rates. However, both devices eliminated this main vortex at all flow rates and reduced the peak aneurysmal velocities by about 90%. A strong correlation between flow diverter porosity and flow reduction was found. In each case the inflow to the aneurysm shifted from the distal neck to the mid- or proximal neck after flow diverter placement.
Even with this relatively simple experimental setup, we were able to observe the major flow field changes, which occurred immediately after the deployment of each flow diverter. Limitations of the study included a simplified geometry and steady-state flow. Constraints included model making and limited availability of flow diverters.
用弹簧圈治疗大型、巨大型和宽颈动脉瘤存在局限性，这使得血流导向装置成为一种有前景的替代方法，可支持对载瘤动脉进行重建。
通过在一个简单的动脉瘤模型上研究两种不同的腔内血流导向装置，使用断层粒子图像测速技术来确定哪种装置能更好地减少流入动脉瘤的血流，并观察动脉瘤内流体结构的任何显著变化，从而评估动脉瘤内流体动力学的变化。
在三种入口流速（18、39和59厘米/秒）下，对具有不同孔隙率的两种血流导向装置直径的模型动脉瘤穹顶和颈部的稳定速度场进行测量，并与无血流导向装置的基线情况进行比较。
在基线情况下，所有流速下动脉瘤穹顶内均存在一个大涡旋。然而，两种装置在所有流速下都消除了这个主要涡旋，并将动脉瘤内的峰值速度降低了约90%。发现血流导向装置的孔隙率与血流减少之间存在很强的相关性。在每种情况下，放置血流导向装置后，动脉瘤的血流从远端颈部转移到中部或近端颈部。
即使在这种相对简单的实验设置下，我们也能够观察到每个血流导向装置部署后立即发生的主要流场变化。该研究的局限性包括几何形状简化和稳态流动。限制因素包括模型制作和血流导向装置的可用性有限。
