Damiano R J, Tutino V M, Paliwal N, Ma D, Davies J M, Siddiqui A H, Meng H
From the Department of Mechanical and Aerospace Engineering (R.J.D., N.P., D.M., H.M.).
Toshiba Stroke and Vascular Research Center (R.J.D., V.M.T., N.P., D.M., J.M.D., A.H.S., H.M.).
AJNR Am J Neuroradiol. 2017 Mar;38(3):603-610. doi: 10.3174/ajnr.A5062. Epub 2017 Jan 5.
Locally compacting the mesh of a flow diverter by a dynamic push-pull technique can accelerate intracranial aneurysm healing. We asked how this deployment strategy compares with overlapping 2 flow diverters for aneurysmal flow reduction.
Using a high-fidelity virtual stent placement method, we simulated 3 flow-diverter strategies (single noncompacted, 2 overlapped, and single compacted) in 3 aneurysms (fusiform, large saccular, and medium saccular). Computational fluid dynamics analysis provided posttreatment hemodynamic parameters, including time-averaged inflow rate, aneurysm-averaged velocity, wall shear stress, total absolute circulation, and turnover time. We examined the relationship between the achieved degree of compaction and aneurysm orifice area.
Flow-diverter compaction resulted in a compaction coverage of 57%, 47%, and 22% over the orifice of the fusiform, large, and medium saccular aneurysm, respectively. Compaction coverage increased linearly with orifice area. In the fusiform aneurysm, the single compacted flow diverter accomplished more aneurysmal flow reduction than the other 2 strategies, as indicated by all 5 hemodynamic parameters. In the 2 saccular aneurysms, the overlapped flow diverters achieved the most flow reduction, followed by the single compacted and the noncompacted flow diverter.
Compacting a single flow diverter can outperform overlapping 2 flow diverters in aneurysmal flow reduction, provided that the compaction produces a mesh denser than 2 overlapped flow diverters and this denser mesh covers a sufficient portion of the aneurysm orifice area, for which we suggest a minimum of 50%. This strategy is most effective for aneurysms with large orifices, especially fusiform aneurysms.
通过动态推拉技术局部压实血流导向装置的网孔可加速颅内动脉瘤愈合。我们探讨了这种植入策略与重叠两个血流导向装置以减少动脉瘤血流相比效果如何。
使用高保真虚拟支架植入方法，我们在3个动脉瘤（梭形、大型囊状和中型囊状）中模拟了3种血流导向装置策略（单个未压实、两个重叠和单个压实）。计算流体动力学分析提供了治疗后的血流动力学参数，包括时间平均流入率、动脉瘤平均速度、壁面剪应力、总绝对循环量和周转时间。我们研究了实现的压实程度与动脉瘤开口面积之间的关系。
血流导向装置压实分别使梭形、大型和中型囊状动脉瘤开口处的压实覆盖率达到57%、47%和22%。压实覆盖率随开口面积线性增加。在梭形动脉瘤中，单个压实的血流导向装置在减少动脉瘤血流方面比其他两种策略更有效，所有5个血流动力学参数均表明了这一点。在两个囊状动脉瘤中，重叠的血流导向装置实现的血流减少最多，其次是单个压实的和未压实的血流导向装置。
压实单个血流导向装置在减少动脉瘤血流方面可能优于重叠两个血流导向装置，前提是压实产生的网孔比两个重叠的血流导向装置更致密，且这种更致密的网孔覆盖动脉瘤开口面积的足够部分，我们建议至少为50%。这种策略对开口大的动脉瘤最有效，尤其是梭形动脉瘤。
