Research Papers

Optimization of Strut Placement in Flow Diverter Stents for Four Different Aneurysm Configurations

[+] Author and Article Information
Hitomi Anzai

Institute of Fluid Science,
2-1-1 Katahira, Aoba-ku, Sendai,
Miyagi 980-8577, Japan
e-mail: anzai@biofluid.ifs.tohoku.ac.jp

Jean-Luc Falcone

University of Geneva,
7 route de Drize,
Carouge CH-1227, Switzerland
e-mail: Jean-Luc.Falcone@unige.ch

Bastien Chopard

University of Geneva,
7 route de Drize,
Carouge CH-1227, Switzerland
e-mail: Bastien.Chopard@unige.ch

Toshiyuki Hayase

Institute of Fluid Science,
Tohoku University,
2-1-1 Katahira, Aoba-ku, Sendai,
Miyagi 980-8577, Japan
e-mail: hayase@ifs.tohoku.ac.jp

Makoto Ohta

Institute of Fluid Science,
Tohoku University,
2-1-1 Katahira, Aoba-ku, Sendai,
Miyagi 980-8577, Japan
e-mail: ohta@biofluid.ifs.tohoku.ac.jp

Contributed by the Bioengineering Division of ASME for publication in the Journal of Biomechanical Engineering. Manuscript received June 18, 2013; final manuscript received April 2, 2014; accepted manuscript posted April 11, 2014; published online May 6, 2014. Assoc. Editor: Francis Loth.

J Biomech Eng 136(6), 061006 (May 06, 2014) (7 pages) Paper No: BIO-13-1266; doi: 10.1115/1.4027411 History: Received June 18, 2013; Revised April 02, 2014; Accepted April 11, 2014

A modern technique for the treatment of cerebral aneurysms involves insertion of a flow diverter stent. Flow stagnation, produced by the fine mesh structure of the diverter, is thought to promote blood clotting in an aneurysm. However, apart from its effect on flow reduction, the insertion of the metal device poses the risk of occlusion of a parent artery. One strategy for avoiding the risk of arterial occlusion is the use of a device with a higher porosity. To aid the development of optimal stents in the view point of flow reduction maintaining a high porosity, we used lattice Boltzmann flow simulations and simulated annealing optimization to investigate the optimal placement of stent struts. We constructed four idealized aneurysm geometries that resulted in four different inflow characteristics and employed a stent model with 36 unconnected struts corresponding to the porosity of 80%. Assuming intracranial flow, steady flow simulation with Reynolds number of 200 was applied for each aneurysm. Optimization of strut position was performed to minimize the average velocity in an aneurysm while maintaining the porosity. As the results of optimization, we obtained nonuniformed structure as optimized stent for each aneurysm geometry. And all optimized stents were characterized by denser struts in the inflow area. The variety of inflow patterns that resulted from differing aneurysm geometries led to unique strut placements for each aneurysm type.

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Appanaboyina, S., Mut, F., Lohner, R., Putman, C., and Cebral, J., 2009, “Simulation of Intracranial Aneurysm Stenting: Techniques and Challenges,” Comput. Methods Appl. Mech. Eng., 198(45-46), pp. 3567–3582. [CrossRef]
Appanaboyina, S., Mut, F., Lohner, R., Scrivano, E., Miranda, C., Lylyk, P., Putman, C., and Cebral, J., 2008, “Computational Modeling of Blood Flow in Side Arterial Branches After Stenting of Cerebral Aneurysms,” Int. J. Comput. Fluid Dyn., 22(10), pp. 669–676. [CrossRef]
Augsburger, L., Farhat, M., Reymond, P., Fonck, E., Kulcsar, Z., Stergiopulos, N., and Rufenacht, D. A., 2009, “Effect of Flow Diverter Porosity on Intra-aneurysmal Blood Flow,” Klin. Neuroradiol., 19(3), pp. 204–214. [CrossRef] [PubMed]
Anzai, H., Ohta, M., Falcone, J.-L., and Chopard, B., 2012, “Optimization of Flow Diverters for Cerebral Aneurysms,” J. Comput. Sci., 3(1-2), pp. 1–7. [CrossRef]
Hirabayashi, M., Ohta, M., Rufenacht, D. A., and Chopard, B., 2003, “Characterization of Flow Reduction Properties in an Aneurysm due to a Stent,” Phy. Rev. E Stat. Nonlin. Soft Matter Phys., 68(2), p. 021918. [CrossRef]
Ionita, C. N., Paciorek, A. M., Hoffmann, K. R., Bednarek, D. R., Yamamoto, J., Kolega, J., Levy, E. I., Hopkins, L. N., Rudin, S., and Mocco, J., 2008, “Asymmetric Vascular Stent: Feasibility Study of a New Low-Porosity Patch-Containing Stent,” Stroke, 39(7), pp. 2105–2113. [CrossRef] [PubMed]
Lieber, B. B., Stancampiano, A. P., and Wakhloo, A. K., 1997, “Alteration of Hemodynamics in Aneurysm Models by Stenting: Influence of Stent Porosity,” Ann. Biomed. Eng., 25(3), pp. 460–469. [CrossRef] [PubMed]
Srinivas, K., Townsend, S., Lee, C. J., Nakayama, T., Ohta, M., Obayashi, S., and Yamaguchi, T., 2010, “Two-Dimensional Optimization of a Stent for an Aneurysm,” ASME J. Med. Devices4(2), p. 021003. [CrossRef]
Nakayama, T., Jeong, S., Srinivas, K., and Ohta, M., 2010, “Development of Stent Strut Pattern for Cerebral Aneurysm,” Proceedings of the 3rd ASME 2010 Joint US-European Fluids Engineering Summer Meeting and 8th International Conference on Nanochannels, Microchannels, and Minichannels, Paper No. FEDSM/ICNMM 2010-30592.
Imai, Y., Sato, K., Ishikawa, T., and Yamaguchi, T., 2008, “Inflow Into Saccular Cerebral Aneurysms at Arterial Bends,” Ann. Biomed. Eng., 36(9), pp. 1489–1495. [CrossRef] [PubMed]
Hoi, Y. M., Meng, H., Woodward, S. H., Bendok, B. R., Hanel, R. A., Guterman, L. R., and Hopkins, L. N., 2004, “Effects of Arterial Geometry on Aneurysm Growth: Three-Dimensional Computational Fluid Dynamics Study,” J. Neurosurg., 101(4), pp. 676–681. [CrossRef] [PubMed]
Anzai, H., Nakayama, T., Takeshima, Y., and Ohta, M., 2010, “The Effect of 3D Visualization on Optimal Design for Strut Position of Intracranial Stent,” Proceedings of the 3rd ASME 2010 Joint US-European Fluids Engineering Summer Meeting and 8th International Conference on Nanochannels, Microchannels, and Minichannels, Paper No. FEDSM/ICNMM 2010-30591.
Janiga, G., Rossl, C., Skalej, M., and Thevenin, D., 2013, “Realistic Virtual Intracranial Stenting and Computational Fluid Dynamics for Treatment Analysis,” J. Biomech., 46(1), pp. 7–12. [CrossRef] [PubMed]
Kim, M., Taulbee, D. B., Tremmel, M., and Meng, H., 2008, “Comparison of Two Stents in Modifying Cerebral Aneurysm Hemodynamics,” Ann. Biomed. Eng., 36(5), pp. 726–741. [CrossRef] [PubMed]
Tremmel, M., Xiang, J., Natarajan, S. K., Hopkins, L. N., Siddiqui, A. H., Levy, E. I., and Meng, H., 2010, “Alteration of Intra-Aneurysmal Hemodynamics for Flow Diversion Using Enterprise and Vision Stents,” World Neurosurg., 74(2-3), pp. 306–315. [CrossRef] [PubMed]
Karino, T., 1986, “Microscopic Structure of Disturbed Flows in the Arterial and Venous Systems and Its Implication in the Localization of Vascular Diseases,” Int. Angiol., 5(4), pp. 297–313. [PubMed]
Axner, L., Hoekstra, A. G., Jeays, A., Lawford, P., Hose, R., and Sloot, P. M. A., 2009, “Simulations of Time Harmonic Blood Flow in the Mesenteric Artery: Comparing Finite Element and Lattice Boltzmann Methods,” Biomed. Eng. Online, 8, p. 23. [CrossRef]
Breuer, M., Bernsdorf, J., Zeiser, T., and Durst, F., 2000, “Accurate Computations of the Laminar Flow Past a Square Cylinder Based on Two Different Methods: Lattice-Boltzmann and Finite-Volume,” Int. J. Heat Fluid Fl., 21(2), pp. 186–196. [CrossRef]
He, X., Duckwiler, G., and Valentino, D. J., 2009, “Lattice Boltzmann Simulation of Cerebral Artery Hemodynamics,” Comput. Fluids, 38(4), pp. 789–796. [CrossRef]
Noble, D. R., Georgiadis, J. G., and Buckius, R. O., 1996, “Comparison of Accuracy and Performance for Lattice Boltzmann and Finite Difference Simulations of Steady Viscous Flow,” Int. J. Numer. Methods Fluid, 23(1), pp. 1–18. [CrossRef]
Succi, S., 2001, The Lattice Boltzmann Equation, for Fluid Dynamics and Beyond, Oxford University Press, UK.
Isoda, H., Hirano, M., Takeda, H., Kosugi, T., Alley, M. T., Markl, M., Pelc, N. J., and Sakahara, H., 2006, “Visualization of Hemodynamics in a Silicon Aneurysm Model Using Time-Resolved, 3D, Phase-Contrast MRI,” ANJR. Am. J. Neuroradiol., 27(5), pp. 1119–1122.
Johnson, D. S., Aragon, C. R., Mcgeoch, L. A., and Schevon, C., 1991, “Optimization by Simulated Annealing—An Experimental Evaluation.2. Graph-Coloring and Number Partitioning,” Operations Res., 39(3), pp. 378–406. [CrossRef]
Kirkpatrick, S., 1984, “Optimization by Simulated Annealing—Quantitative Studies,” J. Stat. Phys., 34(5-6), pp. 975–986. [CrossRef]
Ku, D. N., Giddens, D. P., Zarins, C. K., and Glagov, S., 1985, “Pulsatile Flow and Atherosclerosis in the Human Carotid Bifurcation—Positive Correlation Between Plaque Location and Low and Oscillating Shear-Stress,” Arteriosclerosis, 5(3), pp. 293–302. [CrossRef] [PubMed]
Meng, H., Wang, Z., Hoi, Y., Gao, L., Metaxa, E., Swartz, D. D., and Kolega, J., 2007, “Complex Hemodynamics at the Apex of an Arterial Bifurcation Induces Vascular Remodeling Resembling Cerebral Aneurysm Initiation,” Stroke, 38(6), pp. 1924–1931. [CrossRef] [PubMed]
Shimogonya, Y., Ishikawa, T., Imai, Y., Matsuki, N., and Yamaguchi, T., 2009, “Can Temporal Fluctuation in Spatial Wall Shear Stress Gradient Initiate a Cerebral Aneurysm? A Proposed Novel Hemodynamic Index, the Gradient Oscillatory Number (Gon),” J. Biomech., 42(4), pp. 550–554. [CrossRef] [PubMed]
Ram, D. J., Sreenivas, T. H., and Subramaniam, K. G., 1996, “Parallel Simulated Annealing Algorithms,” J. Parallel Distributed Comput., 37(2), pp. 207–212. [CrossRef]
Liou, T. M., Yi-Chen, L., and Juan, W. C., 2007, “Numerical and Experimental Studies on Pulsatile Flow in Aneurysms Arising Laterally From a Curved Parent Vessel at Various Angles,” J. Biomech., 40(6), pp. 1268–1275. [CrossRef] [PubMed]
Zeng, Z., Durka, M. J., Kallmes, D. F., Ding, Y., and Robertson, A. M., 2011, “Can Aspect Ratio Be Used to Categorize Intra-Aneurysmal Hemodynamics?—A Study of Elastase Induced Aneurysms in Rabbit,” J. Biomech., 44(16), pp. 2809–2816. [CrossRef] [PubMed]


Grahic Jump Location
Fig. 1

Idealized sidewall aneurysms. (a) Straight. (b) U-1. (c) U-3. (d) U-5.

Grahic Jump Location
Fig. 2

Schematic of the stent model

Grahic Jump Location
Fig. 3

Streamlines through the aneurysm neck (left: no stent, center: initial stent, right: optimal stent). (a) Straight. (b) U-1. (c) U-3. (d) U-5.

Grahic Jump Location
Fig. 4

Contour images of the velocity perpendicular to the neck and stent structure. (left: no stent, center: initial stent, right: optimal stent) white circle with dotted line indicates the area where the streamlines enter from the parent artery. (a) Straight. (b) U-1. (c) U-3. (d) U-5.

Grahic Jump Location
Fig. 5

Histogram of velocity component perpendicular to the neck. (a) Straight. (b) U-1. (c) U-3. (d) U-5.



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