前交通动脉动脉瘤支架治疗后血管形态及流体力学数值的模拟研究

目的探讨支架置入治疗前交通动脉宽颈动脉瘤对动脉瘤转归的影响。方法对1例应用支架辅助栓塞前交通动脉宽颈动脉瘤的患者，通过计算流体力学（CFD）有限元方法软件，重建三维血管模型。于支架置入前，截取动脉瘤并修补瘤颈部对应的血管壁，模拟单纯弹簧圈致密栓塞的结果。对比支架置入前后的血管形态改变，分析不同血管形态下的血流动力学参数，包括血液流线、压力及壁面切应力（WSS）等。结果①与单纯弹簧圈致密栓塞对比，支架置入后，血管形态发生明显改变，同侧大脑前动脉A1段和A2段血管夹角增加14．4。；②支架置入后，瘤颈部所对应的血管段内，血液涡流明显减少，流线趋于平直；③单纯弹簧圈致密填塞后瘤颈部平均WSS为11．55Pa，支架置入后，该血管壁平均WSS为7．93Pa，下降31．3％。结论支架置入治疗前交通动脉宽颈动脉瘤可明显改变载瘤动脉的形态，并改变局部载瘤动脉的血流动力学，降低动脉瘤的WSS。

A preliminary study of vascular morphological changes and their numerical simulation of fluid dynamics after anterior communicating artery aneurysms treated with stents

Objective To investigate the outcome of wide-necked anterior communicating artery aneurysm treated with stent placement. Methods One patient with wide-necked anterior communicating artery aneurysm was treated with stent-assisted coil embolization. The three-dimensional blood vessels model was reconstructed by the software of computational fluid dynamics （CFD） finite element method. Before stent placement, the aneurysm was resected and the corresponding vessel wall at the aneurysm neck was repaired to simulate and the results of dense embolization by coils. The changes of vascular morphology before and after the stent placement were compared. The hemodynamic parameters under the different vascular morphologies were analyzed, including blood flow line, pressure, and wall shear stress （WSS） and so on. Results （1）The vascular morphology changed obviously after stent placement as compared to the dense packing with the simple coils,. The vessel angles of ipsilateral anterior cerebral artery A1 and A2 segments increased 14.4 degrees. （2）After stent placement, the blood eddy current reduced significantly at the corresponding vascular segment of the aneurysm neck, and the blood flow line tended to be straight. （3）After dense packing with the simple coils, the mean WSS at the aneurysm neck was 11.5SPa; after stent placement, the mean WSS of the blood vessel wall was 7.93Pa （decreased 31.3% ）. Conclusion The wide-necked anterior communicating artery aneurysm treated with stent placement may significantly change the vascular morphology of parent artery and change the local hemodynamics of parent artery, and reduce the WSS of aneurysm.