不同结构支架植入蜿蜒型动脉瘤的仿真研究
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摘要
管腔内支架治疗技术己发展成为现代医学中备受关注并具有广阔发展前景的微创治疗技术。动脉瘤支架介入治疗的疗效受到诸多因素的影响,包括支架形状(螺旋状、网格状等)、支架丝截面形状、通透率、支架放置位置、支架的连接、支架伸缩性等。
为了探讨不同结构的血管内支架对颅内复杂动脉瘤的血液动力学特性的影响,本文通过CAD软件构建了蜿蜒型颅内动脉瘤和四种不同结构裸支架(截面形状和通透率不同)的三维实体模型,利用计算流体力学方法,借助于有限元软件ANSYS11.0对不同结构内支架分别植入蜿蜒型颅内动脉瘤前后进行仿真研究,提取和分析了支架植入动脉瘤前后瘤腔内的流动情形、压力和壁面切应力等血流动力学参数。
结果表明支架植入动脉瘤后瘤腔内的血流速度被大大削弱,圆顶突起处局部高压力明显减弱,沿瘤腔壁面的压力也得到明显降低并且分布也均衡了很多,末端唇缘处局部高切应力消失了,出现的是较小且均衡的切应力。
设计采用的三角形截面支架由于血液流入和流出时的流阻不同,导致该支架植入动脉瘤后影响瘤腔血流不同,从而产生了动脉瘤腔内的血流动力学明显差异,而优越于传统圆形截面支架。这可以为支架结构设计提供一些理论指导意义。
As a minimally invasive treatment technique, endovascular stent intervention technology has been accepted by modern medicine, which has broad prospective for development. However, the efficacy of stent intervention is affected by many factors, including the stent shape (spiral, grid, etc), cross-section of stent wire, porosity, stent placement, stent connector, stent flexibility and so on.
Endovascular stents with different stent shapes or wire cross-section shapes have different effects on the hemodynamics of basilar aneurysms. In order to get quantitative understanding of this kind of difference, geometrically virtual models of three-dimensional sinuous aneurysms and four types of mesh stents (different porosity and different wire cross-section shapes) were constructed using CAD software, and simulations of stented and nonstented models were performed respectively using finite element software ANSYS11.0 according to CFD method. Hemodynamics data were extracted and analyzed in terms of flow field, pressure and wall shear stress.
The result demonstrated that the velocity of blood flow in stented model is greatly weaken than the nonstented model, and the pressure along the wall of the distal aneurysm is also decreased and more uniform, and the locally elevated WSSs at the proximal lip of the distal aneurysm disappeared, instead small and uniform WSSs distribute along a majority of the aneurismal wall after stent intervention.
It can be concluded that the new type of trianglualr stent with lower porosity has more superiority than other stents in weakening impact of blood to aneurismal wall and decreasing local high pressure and WSS. The flow resistance of the new stent with triangular cross-section is different when blood flows in and out of the aneurismal sac, and thus brings about different hemodynamics in aneurysms after the stent intervention. The stent with triangle section is more suitable for sinuous basilar aneurysms comparatively. The present study can provide some theoretical guidance to structural design of endovascular stent.
为了探讨不同结构的血管内支架对颅内复杂动脉瘤的血液动力学特性的影响,本文通过CAD软件构建了蜿蜒型颅内动脉瘤和四种不同结构裸支架(截面形状和通透率不同)的三维实体模型,利用计算流体力学方法,借助于有限元软件ANSYS11.0对不同结构内支架分别植入蜿蜒型颅内动脉瘤前后进行仿真研究,提取和分析了支架植入动脉瘤前后瘤腔内的流动情形、压力和壁面切应力等血流动力学参数。
结果表明支架植入动脉瘤后瘤腔内的血流速度被大大削弱,圆顶突起处局部高压力明显减弱,沿瘤腔壁面的压力也得到明显降低并且分布也均衡了很多,末端唇缘处局部高切应力消失了,出现的是较小且均衡的切应力。
设计采用的三角形截面支架由于血液流入和流出时的流阻不同,导致该支架植入动脉瘤后影响瘤腔血流不同,从而产生了动脉瘤腔内的血流动力学明显差异,而优越于传统圆形截面支架。这可以为支架结构设计提供一些理论指导意义。
As a minimally invasive treatment technique, endovascular stent intervention technology has been accepted by modern medicine, which has broad prospective for development. However, the efficacy of stent intervention is affected by many factors, including the stent shape (spiral, grid, etc), cross-section of stent wire, porosity, stent placement, stent connector, stent flexibility and so on.
Endovascular stents with different stent shapes or wire cross-section shapes have different effects on the hemodynamics of basilar aneurysms. In order to get quantitative understanding of this kind of difference, geometrically virtual models of three-dimensional sinuous aneurysms and four types of mesh stents (different porosity and different wire cross-section shapes) were constructed using CAD software, and simulations of stented and nonstented models were performed respectively using finite element software ANSYS11.0 according to CFD method. Hemodynamics data were extracted and analyzed in terms of flow field, pressure and wall shear stress.
The result demonstrated that the velocity of blood flow in stented model is greatly weaken than the nonstented model, and the pressure along the wall of the distal aneurysm is also decreased and more uniform, and the locally elevated WSSs at the proximal lip of the distal aneurysm disappeared, instead small and uniform WSSs distribute along a majority of the aneurismal wall after stent intervention.
It can be concluded that the new type of trianglualr stent with lower porosity has more superiority than other stents in weakening impact of blood to aneurismal wall and decreasing local high pressure and WSS. The flow resistance of the new stent with triangular cross-section is different when blood flows in and out of the aneurismal sac, and thus brings about different hemodynamics in aneurysms after the stent intervention. The stent with triangle section is more suitable for sinuous basilar aneurysms comparatively. The present study can provide some theoretical guidance to structural design of endovascular stent.
引文
1 Parodi JC, Palmaz JC, Barone HD. Transfemoral intraluminal graft implantation for abdominal aortic aneurysms. Ann Vasc Surg. 1991, 5:491~499
2 Brian LH, Christopher MP, Ronald FB. Combined surgical and endovascular techniques of flow alteration to treat fusiform and complex wide-necked intracranial aneurysms that are unsuitable for clipping or coil embolization. J Neurosurg. 2001, 95(1):24~35
3 Gonzalez NR, Duckwiler G, Jahan R, et a1. Challenges in the endovascular treatment of giant intracranial aneurysms. Neurosurgery, 2006, 59:113~124
4 Nishi S, Nakayama Y, Ishibashi-Ueda H, et al. Occlusion of experimental aneurysms with heparin-loaded microporous stent grafts. Neurosurgery. 2003, 53(6):1397~1405
5田彦龙,宋冬雷.血管内支架治疗颅内复杂性动脉瘤的实验与临床研究.中国临床神经科学. 2006, 14(5):533~537
6 Koceral N, Kizikilica O, Albayrama S, et al. Treatment of iatrogenis internal carotid artery laceration and carotid cavernous fistula with endovascular stent-graft placement. AJNR. 2002, 23(3):442~446
7 Vanninen R, Manninen H, Ronkainen A. Broad based intracranial aneurysms: thrombosis induced by stent placement. AJNR. 2003, 24:263~266
8 Marks MP, Dake MD, Steinberg GK, et al. Stent placement for arterial and venous cerebro-vascular disease: preliminary experience. Neuroradiology. 1994, 191:441~446
9 Rhee K, Han MH, Cha SH. Changes of flow characteristics by stenting in aneurysm models: influence of aneurysm geometry and stent porosity. Ann Biomed Eng. 2002, 30(7):894~904
10 Charles Vega, Jeremiah V, Sean D, et al. Intracranial aneurysms: Current evidence and clinical practice. American Family Physician. 2002, 66: 601-608
11 Lieber BB, Livescu V, Hopkins LN, et a1. Particle image velocimetry assessment of stent design influence on intra-aneurysmal flow. Ann Biomed Eng. 2002, 30(6):768~777
12 Lieber BB, Gounis MJ. The physics of endoluminal stenting in the treatment of cerebrovascular aneurysms. NeurolRes. 2002, 24(S1):33~42
13梁栋科,杨大智.不同设计心血管支架的血流动力学分析.生物医学工程学杂志. 2006, 23(6):1241~1244
14 Higashida RT, Smith W, Gress D, et al. Intravascular stent and endovascular coil placement for a ruptured fusiform aneurysm of the basilar artery: case report andreview of the literature. Neurosurg. 1997, 87(6):944~949
15 Horowitz B, Levy EI, Koebbe J, et al. Transluminal stent-assisted coil embolization of a vertebral confluence aneurysm technique report. SurgNeurol. 2001, 55:291~296
16吴中学,王忠诚,张友平等.微弹簧圈血管内栓塞治疗205例颅内囊状动脉瘤.中华神经外科杂志. 1997, 13(6):323~326
17吕明,吴中学.颅内动脉瘤血管内治疗进展.中华神经医学杂志. 2005, 4(9): 963~966
18 Biondi A, Janardhan V, Katz JM, et al. Neuroform stent-assisted coil embolization of wide-neck intracranial aneurysms: strategies in stent deployment and midterm follow-up. Neurosurgery. 2007, 61(3):460~468
19 Benitez RP, Silva MT, Klem J, et al. Endovascular occlusion of wide-necked aneurysms with a new intracranial microstent (Neuroform) and detachable coils. Neurosurgery. 2004, 54(6):1359~1368
20 Lylyk P, Ferrario A, Pasbon B, et al. Buenos Aires experirience using the neuroform stent for the treatment of intracranial aneurysms. Neurosurg. 2005, 102(2):235~241
21 Serruys PW, Jaegere P, Kiemeneij F, et a1. A comparison of balloon expandable stent imp lantation with balloon angiop lasty in patients with coronary artery disease. N Engl J Med. 1994, 331(8):489~495
22曲友直,赵振伟,高国栋等.颅内宽颈动脉瘤的血管内治疗.中华神经外科疾病研究杂志. 2007, 6(2):111~114
23 Aenis AP, Stancampiano AK, Lieber BB. Modeling of flow in a straight stented and nonstented side wall aneurysm model. Biomech Eng. 1997, 119: 206~212
24 Groden C, Laudan J, Gatchell S. Three-dimensional pulsatile flow simulation before and after endovascular coil embolization of a terminal cerebral aneurysm. Cereb Blood Flow Metab. 2001, 21:1464~1471
25 Liou TM, and Liou SN. Pulsatile flows in a lateral aneurysm anchored on a stented and curved parent vessel. Exp Mech. 2004, 44:253~260
26 Stuhne GR, Steinman DA. Finite element modeling of the hemodynamics of stented aneurysms. Biomech Eng. 2004, 126:382~387
27 Steinman DA, Miliner JS, Norley CJ, et al. Image-based computational simulation of flow dynamics in a giant intracranial aneurysm. Am J Neruoradiol. 2003, 24:559~566
28 Radalli AG, Augsburger L, Cebral JR, et al. Reproducibility of hemodynamical simulations in a subject-specific stented aneurysm model-a report on the Virtual Intracranial Stenting Challenge 2007. J Biomech. 2008, 41(10):2069~2081
29 Elger DF, Blackketter DM, Budwig RS et al. The influence of shape on the stresses in model abdominal aortic aneurysms. Biomech Eng. 1996, 118:26~332
30乔爱科,刘有军,张松.支架治疗主动脉弓内侧动脉瘤的仿真研究.生物医学工程学杂志. 2007, 24(4):852~856
31乔爱科,刘有军.半桥支架治疗主动脉弓动脉瘤的仿真研究.北京工业大学学报. 2007, 33(4):423~427
32梁栋科,杨大智,齐民.一种血管内支架的有限元模型及计算流体动力学分析.生物医学工程学杂志. 2007, 24(3):549~553
33 Minsuok KM,Dale BT,Markus Tremmel,et al. Comparison of two stent in modifying cerebral aneurysm hemodynamics. Annals of Biomedical Engineering. 2008, 36:726~741
34 Inzoli F, Boschetti F, Zappa M, et al. Biomechanical factors in abdominal aortic aneurysm rupture. Eur J Vasc Surg. 1993, 7:667~674
35 Vorp DA, Raghavan ML and Webster MW. Mechanical wall stress in abdominal aortic aneurysm: influence of diameter and asymmetry. J Vasc Surg. 1998, 27: 632~639
36 Gonzalez CF, Cho YL, Ortega HV et al. Intracranial aneurysms: flow analysis of their origin and progression. Am J Neuroradiol 1992. 13:181~188
37 Burleson AC, Strother CM and Turitto VT. Computer modeling of intracranial saccular and lateral aneurysms for the study of their hemodynamics. Neurosurgery. 1995, 37:774~784
38 Ernemann UU, Gr?new?ller E, Duffner FB et al. Influence of geometric and hemodynamic parameters on aneurysm visualization during three-drmensional rotational angiography: an in vitro study. Am J Neuroradiol. 2003, 24: 597~603
39 Foutrakis GN, Yonas H and Sclabassi RJ. Saccular aneurysm formation in curved and bifurcating arteries. Am J Neuroradiol. 1999, 20:1309~1317
40 Liou TM, Chang WC and Liao CC. Experimental study of steady and pulsatile flows in cerebral aneurysm model of various sizes at branching site. ASME J Biomech Eng. 1997, 119:325~332
41 Liou TM, Chang WC and Liao CC. LDV measurements in lateral model aneurysms of various sizes. Experiments Fluids. 1997, 23: 317~324
42 Liou TM, Liao CC. Flowfields in lateral aneurysm arising from parent vessels with different curvatures using PTV. Experiments in Fluids. 1997, 23:288~298
43 Liou TM, Liou SN. A Review on In Vitro Studies of Hemodynamic Characteristics in Terminal and Lateral Aneurysm Models. Proc Natl Sci Counc. ROC. 1999, 23:133~148
44 L?w M, Perktold K and Rauning R. Hemodynamics in rigid and distensible saccular aneurysms: a numerical study of pulsatile flow characteristics. Biorheology. 1993, 30:287~298
45 Hassan T, Ezura M, Timofeev EV, et al. Computational simulation of therapeutic parent artery occlusion to treat giant vertebrobasilar aneurysm. Am J Neuroradiol.2004, 25:63~68
46 Tateshima S, Murayama Y, Villablanca JP, et al. In Vitro Measurement of fluid-Induced wall shear stress in unruptured cerebral aneurysms harboring blebs. Stroke. 2003, 34:187~192
47 Fry DL, Certain histological and chemical responses of the vascular interface to acutely induced mechanical stress in the aorta of the dog. Cir Res. 1969, 14: 93~108
48 Alvaro V, Sergio B, Juan S, et al. Comparison of haemodynamics in cerebral aneurysms of different sizes located in the ophthalmic artery. Numer Meth Fluids. 2007, 53:793~809
49蔡彦,许世雄,景在平等.腹主动脉瘤几何形态对血液动力学影响的三维数值分析.医用生物力学, 2008, 23(2):140-146
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60 Raghavan M, Harbaugh R. Quantified aneurysm shape and rupture risk. Journal of Neurosurgery, 2005, 102:355~362
61 Baruch B, Alfred P, Ajay K, et al. Alteration of hemodynamics in aneurysm models by stenting: influence of stent porosity. Annals of Biomedical Engineering. 1997, 25:460~469
62 Tongmiin Liou, Yichen Li. Effects of stent porosity on hemodynamics in a sidewall aneurysm model. Journal of Biomechanics. 2008, 41:1174~1183
63 Barath KF, Cassot DA, Rufenacht, et a1. Anatomically shaped internal carotid artery aneurysm in vitro model for flow analysis to evaluate stent effect.AJNR. 2004, 25:1750~1759
64 Meng HZ, Wang M, Kim, et a1. Saceular aneurysms on straight and curved vessels are subject to different hemodynamics:implications of intravascular stenting. MNR, 2006, 27:1861~1865
65 Barath K, Cassot F, Fasel JH, et a1.Influence of stent properties on the alteration of cerebral intra-aneurismal haemodynamics: flow quantification in elastic sidewall aneurysm model. Neurol Res. 2005, 27 Suppl 1:S120~S128
66 Liou TM, Liou SN, Chu KL. Intra aneurysmal flow with helix and mesh stent placement across side-wall aneurysm pore of a straight parent vessel. J Biomech Engl, 2004, 126:36~43
67 Masaaki S, Marie O, Kiyoshi T, et a1. Magnitude and role of wall shear stress on cerebral aneurysm computational fluid dynamic study of 20 middle cerebral artery aneurysms. Stroke, 2004, 35:2500~2505
2 Brian LH, Christopher MP, Ronald FB. Combined surgical and endovascular techniques of flow alteration to treat fusiform and complex wide-necked intracranial aneurysms that are unsuitable for clipping or coil embolization. J Neurosurg. 2001, 95(1):24~35
3 Gonzalez NR, Duckwiler G, Jahan R, et a1. Challenges in the endovascular treatment of giant intracranial aneurysms. Neurosurgery, 2006, 59:113~124
4 Nishi S, Nakayama Y, Ishibashi-Ueda H, et al. Occlusion of experimental aneurysms with heparin-loaded microporous stent grafts. Neurosurgery. 2003, 53(6):1397~1405
5田彦龙,宋冬雷.血管内支架治疗颅内复杂性动脉瘤的实验与临床研究.中国临床神经科学. 2006, 14(5):533~537
6 Koceral N, Kizikilica O, Albayrama S, et al. Treatment of iatrogenis internal carotid artery laceration and carotid cavernous fistula with endovascular stent-graft placement. AJNR. 2002, 23(3):442~446
7 Vanninen R, Manninen H, Ronkainen A. Broad based intracranial aneurysms: thrombosis induced by stent placement. AJNR. 2003, 24:263~266
8 Marks MP, Dake MD, Steinberg GK, et al. Stent placement for arterial and venous cerebro-vascular disease: preliminary experience. Neuroradiology. 1994, 191:441~446
9 Rhee K, Han MH, Cha SH. Changes of flow characteristics by stenting in aneurysm models: influence of aneurysm geometry and stent porosity. Ann Biomed Eng. 2002, 30(7):894~904
10 Charles Vega, Jeremiah V, Sean D, et al. Intracranial aneurysms: Current evidence and clinical practice. American Family Physician. 2002, 66: 601-608
11 Lieber BB, Livescu V, Hopkins LN, et a1. Particle image velocimetry assessment of stent design influence on intra-aneurysmal flow. Ann Biomed Eng. 2002, 30(6):768~777
12 Lieber BB, Gounis MJ. The physics of endoluminal stenting in the treatment of cerebrovascular aneurysms. NeurolRes. 2002, 24(S1):33~42
13梁栋科,杨大智.不同设计心血管支架的血流动力学分析.生物医学工程学杂志. 2006, 23(6):1241~1244
14 Higashida RT, Smith W, Gress D, et al. Intravascular stent and endovascular coil placement for a ruptured fusiform aneurysm of the basilar artery: case report andreview of the literature. Neurosurg. 1997, 87(6):944~949
15 Horowitz B, Levy EI, Koebbe J, et al. Transluminal stent-assisted coil embolization of a vertebral confluence aneurysm technique report. SurgNeurol. 2001, 55:291~296
16吴中学,王忠诚,张友平等.微弹簧圈血管内栓塞治疗205例颅内囊状动脉瘤.中华神经外科杂志. 1997, 13(6):323~326
17吕明,吴中学.颅内动脉瘤血管内治疗进展.中华神经医学杂志. 2005, 4(9): 963~966
18 Biondi A, Janardhan V, Katz JM, et al. Neuroform stent-assisted coil embolization of wide-neck intracranial aneurysms: strategies in stent deployment and midterm follow-up. Neurosurgery. 2007, 61(3):460~468
19 Benitez RP, Silva MT, Klem J, et al. Endovascular occlusion of wide-necked aneurysms with a new intracranial microstent (Neuroform) and detachable coils. Neurosurgery. 2004, 54(6):1359~1368
20 Lylyk P, Ferrario A, Pasbon B, et al. Buenos Aires experirience using the neuroform stent for the treatment of intracranial aneurysms. Neurosurg. 2005, 102(2):235~241
21 Serruys PW, Jaegere P, Kiemeneij F, et a1. A comparison of balloon expandable stent imp lantation with balloon angiop lasty in patients with coronary artery disease. N Engl J Med. 1994, 331(8):489~495
22曲友直,赵振伟,高国栋等.颅内宽颈动脉瘤的血管内治疗.中华神经外科疾病研究杂志. 2007, 6(2):111~114
23 Aenis AP, Stancampiano AK, Lieber BB. Modeling of flow in a straight stented and nonstented side wall aneurysm model. Biomech Eng. 1997, 119: 206~212
24 Groden C, Laudan J, Gatchell S. Three-dimensional pulsatile flow simulation before and after endovascular coil embolization of a terminal cerebral aneurysm. Cereb Blood Flow Metab. 2001, 21:1464~1471
25 Liou TM, and Liou SN. Pulsatile flows in a lateral aneurysm anchored on a stented and curved parent vessel. Exp Mech. 2004, 44:253~260
26 Stuhne GR, Steinman DA. Finite element modeling of the hemodynamics of stented aneurysms. Biomech Eng. 2004, 126:382~387
27 Steinman DA, Miliner JS, Norley CJ, et al. Image-based computational simulation of flow dynamics in a giant intracranial aneurysm. Am J Neruoradiol. 2003, 24:559~566
28 Radalli AG, Augsburger L, Cebral JR, et al. Reproducibility of hemodynamical simulations in a subject-specific stented aneurysm model-a report on the Virtual Intracranial Stenting Challenge 2007. J Biomech. 2008, 41(10):2069~2081
29 Elger DF, Blackketter DM, Budwig RS et al. The influence of shape on the stresses in model abdominal aortic aneurysms. Biomech Eng. 1996, 118:26~332
30乔爱科,刘有军,张松.支架治疗主动脉弓内侧动脉瘤的仿真研究.生物医学工程学杂志. 2007, 24(4):852~856
31乔爱科,刘有军.半桥支架治疗主动脉弓动脉瘤的仿真研究.北京工业大学学报. 2007, 33(4):423~427
32梁栋科,杨大智,齐民.一种血管内支架的有限元模型及计算流体动力学分析.生物医学工程学杂志. 2007, 24(3):549~553
33 Minsuok KM,Dale BT,Markus Tremmel,et al. Comparison of two stent in modifying cerebral aneurysm hemodynamics. Annals of Biomedical Engineering. 2008, 36:726~741
34 Inzoli F, Boschetti F, Zappa M, et al. Biomechanical factors in abdominal aortic aneurysm rupture. Eur J Vasc Surg. 1993, 7:667~674
35 Vorp DA, Raghavan ML and Webster MW. Mechanical wall stress in abdominal aortic aneurysm: influence of diameter and asymmetry. J Vasc Surg. 1998, 27: 632~639
36 Gonzalez CF, Cho YL, Ortega HV et al. Intracranial aneurysms: flow analysis of their origin and progression. Am J Neuroradiol 1992. 13:181~188
37 Burleson AC, Strother CM and Turitto VT. Computer modeling of intracranial saccular and lateral aneurysms for the study of their hemodynamics. Neurosurgery. 1995, 37:774~784
38 Ernemann UU, Gr?new?ller E, Duffner FB et al. Influence of geometric and hemodynamic parameters on aneurysm visualization during three-drmensional rotational angiography: an in vitro study. Am J Neuroradiol. 2003, 24: 597~603
39 Foutrakis GN, Yonas H and Sclabassi RJ. Saccular aneurysm formation in curved and bifurcating arteries. Am J Neuroradiol. 1999, 20:1309~1317
40 Liou TM, Chang WC and Liao CC. Experimental study of steady and pulsatile flows in cerebral aneurysm model of various sizes at branching site. ASME J Biomech Eng. 1997, 119:325~332
41 Liou TM, Chang WC and Liao CC. LDV measurements in lateral model aneurysms of various sizes. Experiments Fluids. 1997, 23: 317~324
42 Liou TM, Liao CC. Flowfields in lateral aneurysm arising from parent vessels with different curvatures using PTV. Experiments in Fluids. 1997, 23:288~298
43 Liou TM, Liou SN. A Review on In Vitro Studies of Hemodynamic Characteristics in Terminal and Lateral Aneurysm Models. Proc Natl Sci Counc. ROC. 1999, 23:133~148
44 L?w M, Perktold K and Rauning R. Hemodynamics in rigid and distensible saccular aneurysms: a numerical study of pulsatile flow characteristics. Biorheology. 1993, 30:287~298
45 Hassan T, Ezura M, Timofeev EV, et al. Computational simulation of therapeutic parent artery occlusion to treat giant vertebrobasilar aneurysm. Am J Neuroradiol.2004, 25:63~68
46 Tateshima S, Murayama Y, Villablanca JP, et al. In Vitro Measurement of fluid-Induced wall shear stress in unruptured cerebral aneurysms harboring blebs. Stroke. 2003, 34:187~192
47 Fry DL, Certain histological and chemical responses of the vascular interface to acutely induced mechanical stress in the aorta of the dog. Cir Res. 1969, 14: 93~108
48 Alvaro V, Sergio B, Juan S, et al. Comparison of haemodynamics in cerebral aneurysms of different sizes located in the ophthalmic artery. Numer Meth Fluids. 2007, 53:793~809
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