Abstract
The aim of this study was to demonstrate quantitatively and qualitatively the hemodynamic changes in abdominal aortic aneurysms (AAA) after stent-graft placement based on multidetector CT angiography (MDCT-A) datasets using the possibilities of computational fluid dynamics (CFD). Eleven patients with AAA and one patient with left-side common iliac aneurysm undergoing MDCT-A before and after stent-graft implantation were included. Based on the CT datasets, three-dimensional grid-based models of AAA were built. The minimal size of tetrahedrons was determined for grid-independence simulation. The CFD program was validated by comparing the calculated flow with an experimentally generated flow in an identical, anatomically correct silicon model of an AAA. Based on the results, pulsatile flow was simulated. A laminar, incompressible flow-based inlet condition, zero traction-force outlet boundary, and a no-slip wall boundary condition was applied. The measured flow volume and visualized flow pattern, wall pressure, and wall shear stress before and after stent-graft implantation were compared. The experimentally and numerically generated streamlines are highly congruent. After stenting, the simulation shows a reduction of wall pressure and wall shear stress and a more equal flow through both external iliac arteries after stenting. The postimplantation flow pattern is characterized by a reduction of turbulences. New areas of high pressure and shear stress appear at the stent bifurcation and docking area. CFD is a versatile and noninvasive tool to demonstrate changes of flow rate and flow pattern caused by stent-graft implantation. The desired effect and possible complications of a stent-graft implantation can be visualized. CFD is a highly promising technique and improves our understanding of the local structural and fluid dynamic conditions for abdominal aortic stent placement.
Similar content being viewed by others
References
Johnston KW, Rutherford RB, Tilson MD, et al. (1991) Suggested standards for reporting on arterial aneurysms. Subcommittee on Reporting Standards for Arterial Aneurysms, Ad Hoc Committee on Reporting Standards, Society for Vascular Surgery and North American Chapter, International Society for Cardiovascular Surgery. J Vasc Surg 13:452–458
Alcorn HG, Wolfson SK Jr, Sutton-Tyrrell K, et al. (1996) Risk factors for abdominal aortic aneurysms in older adults enrolled in The Cardiovascular Health Study. Arterioscler Thromb Vasc Biol 16:963–970
Nevitt MP, Ballard DJ, Hallett JW Jr. (1989) Prognosis of abdominal aortic aneurysms. A population-based study. N Engl J Med 321:1009–1014
Glimaker H, Holmberg L, Elvin A, et al. (1991) Natural history of patients with abdominal aortic aneurysm. Eur J Vasc Surg 5:125–130
Rydberg J, Kopecky KK, Johnson MS, et al. (2001) Endovascular repair of abdominal aortic aneurysms: assessment with multislice CT. Am J Roentgenol 177:607–614
Chong CK, How TV (2004) Flow patterns in an endovascular stent-graft for abdominal aortic aneurysm repair. J Biomech 37:89–97
Di Martino ES, Guadagni G, Fumero A, et al. (2001) Fluid–structure interaction within realistic three-dimensional models of the aneurysmatic aorta as a guidance to assess the risk of rupture of the aneurysm. Med Eng Phys 23:647–655
Fillinger MF, Raghavan ML, Marra SP, et al. (2002) In vivo analysis of mechanical wall stress and abdominal aortic aneurysm rupture risk. J Vasc Surg 36:589–597
Juchems MS, Pless D, Fleiter TR, et al. (2004) [Non-invasive, multi detector row (MDR) CT based computational fluid dynamics (CFD) analysis of hemodynamics in infrarenal abdominal aortic aneurysm (AAA) before and after endovascular repair]. Rofo 176:56–61
Li Z, Kleinstreuer C (2005) Fluid–structure interaction effects on sac-blood pressure and wall stress in a stented aneurysm. J Biomech Eng 127:662–671
Li Z, Kleinstreuer C (2005) Blood flow and structure interactions in a stented abdominal aortic aneurysm model. Med Eng Phys 27:369–382
Liffman K, Lawrence-Brown MM, Semmens JB, et al. (2001) Analytical modeling and numerical simulation of forces in an endoluminal graft. J Endovasc Ther 8:358–371
Perktold K, Hofer M, Rappitsch G, et al. (1998) Validated computation of physiologic flow in a realistic coronary artery branch. J Biomech 31:217–228
Raghavan ML, Vorp DA, Federle MP, et al. (2000) Wall stress distribution on three-dimensionally reconstructed models of human abdominal aortic aneurysm. J Vasc Surg 31:760–769
Walsh PW, Chin-Quee S, Moore JE Jr (2003) Flow changes in the aorta associated with the deployment of a AAA stent graft. Med Eng Phys 25:299–307
Wang DH, Makaroun MS, Webster MW, et al. (2002) Effect of intraluminal thrombus on wall stress in patient-specific models of abdominal aortic aneurysm. J Vasc Surg 36:598–604
Kumar BV, Naidu KB (1995) Finite element analysis of nonlinear pulsatile suspension flow dynamics in blood vessels with aneurysm. Comput Biol Med 25:1–20
Redaelli A, Boschetti F, Inzoli F (1997) The assignment of velocity profiles in finite element simulations of pulsatile flow in arteries. Comput Biol Med 27:233–247
Berger SA, Goldsmith W, Lewis ER (eds.) 2000 Introduction to Bioengineering Oxford: Oxford University Press, UK
Moore JA, Steinman DA, Holdsworth DW, et al. (1999) Accuracy of computational hemodynamics in complex arterial geometries reconstructed from magnetic resonance imaging. Ann Biomed Eng 27:32–41
Papathanasopoulou P, Zhao S, Kohler U, et al. (2003) MRI measurement of time-resolved wall shear stress vectors in a carotid bifurcation model, and comparison with CFD predictions. J Magn Reson Imag 17:153–162
Long Q, Xu XY, Bourne M, et al. (2000) Numerical study of blood flow in an anatomically realistic aorto-iliac bifurcation generated from MRI data. Magn Reson Med 43:565–576
Egelhoff CJ, Budwig RS, Elger DF, et al. (1999) Model studies of the flow in abdominal aortic aneurysms during resting and exercise conditions. J Biomech 32:1319–1329
Ferrandez A, David T, Bamford J, et al. (2000) Computational models of blood flow in the circle of Willis. Comput Methods Biomech Biomed Eng 4:1–26
Mijovic B, Liepsch D (2003) Experimental flow studies in an elastic Y-model. Technol Health Care 11:115–141
Berry E, Marsden A, Dalgarno KW, et al. (2002) Flexible tubular replicas of abdominal aortic aneurysms. Proc Inst Mech Eng [H] 216:211–214
Knox K, Kerber CW, Singel SA, et al. (2005) Rapid prototyping to create vascular replicas from CT scan data: making tools to teach, rehearse, and choose treatment strategies. Catheter Cardiovasc Intervent 65:47–53
Kramer SC, Seifarth H, Pamler R, et al. (2001) Geometric changes in aortic endografts over a 2-year observation period. J Endovasc Ther 8:34–38
Mohan IV, Harris PL, Van Marrewijk CJ, et al. (2002) Factors and forces influencing stent-graft migration after endovascular aortic aneurysm repair. J Endovasc Ther 9:748–755
Zarins CK, Bloch DA, Crabtree T, et al. (2003) Stent graft migration after endovascular aneurysm repair: importance of proximal fixation. J Vasc Surg 38:1264–1272; discussion 1272
Alric P, Hinchliffe RJ, MacSweeney ST, et al. (2002) The zenith aortic stent-graft: A 5-year single-center experience. J Endovasc Ther 9:719–728
Matsumura JS, Katzen BT, Hollier LH, et al. (2001) Update on the bifurcated EXCLUDER endoprosthesis: phase I results. J Vasc Surg 33:S150–S153
Ohki T, Veith FJ, Shaw P, et al. (2001) Increasing incidence of midterm and long-term complications after endovascular graft repair of abdominal aortic aneurysms: A note of caution based on a 9-year experience. Ann Surg 234:323–334; discussion 334–325
White GH, May J, Petrasek P, et al. (1999) Endotension: An explanation for continued AAA growth after successful endoluminal repair. J Endovasc Surg 6:308–315
Willneff J (2002) 3D particle tracking velocimentry based on image and object space information. In:ISPRS Commission V Symposium, International Archives of Photography, Remote Sensing and Information Sience. Corfu, Greece, 2002, Part 5
Author information
Authors and Affiliations
Corresponding author
Additional information
An erratum to this article is available at http://dx.doi.org/10.1007/s00270-005-8227-z.
Rights and permissions
About this article
Cite this article
Frauenfelder, T., Lotfey, M., Boehm, T. et al. Computational Fluid Dynamics: Hemodynamic Changes in Abdominal Aortic Aneurysm After Stent-Graft Implantation. Cardiovasc Intervent Radiol 29, 613–623 (2006). https://doi.org/10.1007/s00270-005-0227-5
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00270-005-0227-5