Numerical Study on the Hazards of Gravitational Forces on Cerebral Aneurysms

Authors: Hashem M. Alargha, Mohammad O. Hamdan, Waseem H. Aziz

Abstract:

Aerobatic and military pilots are subjected to high gravitational forces that could cause blackout, physical injuries or death. A CFD simulation using fluid-solid interactions scheme has been conducted to investigate the gravitational effects and hazards inside cerebral aneurysms. Medical data have been used to derive the size and geometry of a simple aneurysm on a T-shaped bifurcation. The results show that gravitational force has no effect on maximum Wall Shear Stress (WSS); hence, it will not cause aneurysm initiation/formation. However, gravitational force cause causes hypertension which could contribute to aneurysm rupture.

Keywords: Aneurysm, CFD, wall shear stress, gravity, fluid dynamics, bifurcation artery.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1124425

References:

[1] T. Nakagawa and K. Hashi, "The incidence and treatment of asymptomatic, unruptured cerebral aneurysms," Journal of neurosurgery, vol. 80, pp. 217-223, 1994.
[2] T. Otani, M. Nakamura, T. Fujinaka, M. Hirata, J. Kuroda, K. Shibano, et al., "Computational fluid dynamics of blood flow in coil-embolized aneurysms: effect of packing density on flow stagnation in an idealized geometry," Medical & biological engineering & computing, vol. 51, pp. 901-910, 2013.
[3] G. J. Rinkel, M. Djibuti, A. Algra, and J. Van Gijn, "Prevalence and risk of rupture of intracranial aneurysms a systematic review," Stroke, vol. 29, pp. 251-256, 1998.
[4] I. Madrazo, A. Noyola, C. Piña, A. Graef, M. Olhagaray, S. Gutiérrez, et al., "(Effect of position with respect to gravitational force on the hydrodynamics of an experimental model of saccular aneurysm)," Archivos de investigacion medica, vol. 21, pp. 103-113, 1989.
[5] D. Beaudette, "A hazard in aerobatics: Effects of G-forces on pilots," FAA advisory circular, pp. 91-61, 1984.
[6] M. Senegor, "Traumatic pericallosal aneurysm in a patient with no major trauma: Case report," Journal of neurosurgery, vol. 75, pp. 475-477, 1991.
[7] C. Sherif, G. Kleinpeter, G. Mach, M. Loyoddin, T. Haider, R. Plasenzotti, et al., "Evaluation of cerebral aneurysm wall thickness in experimental aneurysms: Comparison of 3T-MR imaging with direct microscopic measurements," Acta neurochirurgica, vol. 156, pp. 27-34, 2014.
[8] V. Costalat, M. Sanchez, D. Ambard, L. Thines, N. Lonjon, F. Nicoud, et al., "Biomechanical wall properties of human intracranial aneurysms resected following surgical clipping (IRRAs Project)," Journal of biomechanics, vol. 44, pp. 2685-2691, 2011.
[9] Y. Bazilevs, M.-C. Hsu, Y. Zhang, W. Wang, T. Kvamsdal, S. Hentschel, et al., "Computational vascular fluid–structure interaction: methodology and application to cerebral aneurysms," Biomechanics and modeling in mechanobiology, vol. 9, pp. 481-498, 2010.
[10] H. M. AlArgha, M. O. Hamdan, A. Elshawarby, and W. H. Aziz, "CFD Sensitivity study for Newtonian viscosity model in cerebral aneurysms," presented at the Eleventh International Conference on Computational Fluid Dynamics in the Minerals and Process Industries, Melbourne, Australia, 2015.
[11] M. W. Siebert and P. S. Fodor, "Newtonian and non-newtonian blood flow over a backward-facing step–a case study," in Proceedings of the COMSOL Conference, Boston, 2009.
[12] J. D. Humphrey and S. DeLange, An introduction to biomechanics: solids and fluids, analysis and design: Springer Science & Business Media, 2013.
[13] R. G. Gosling and M. M. Budge, "Terminology for describing the elastic behavior of arteries," Hypertension, vol. 41, pp. 1180-1182, 2003.
[14] W. Nichols, M. O'Rourke, and C. Vlachopoulos, McDonald's blood flow in arteries: theoretical, experimental and clinical principles: CRC Press, 2011.
[15] Y. M. Abdulrazzaq, M. A. Moussa, and N. Nagelkerke, "National growth charts for the United Arab Emirates," Journal of epidemiology, vol. 18, pp. 295-303, 2008.
[16] Y. Zhang, W. Chong, and Y. Qian, "Investigation of intracranial aneurysm hemodynamics following flow diverter stent treatment," Medical engineering & physics, vol. 35, pp. 608-615, 2013.
[17] M. Shojima, M. Oshima, K. Takagi, R. Torii, M. Hayakawa, K. Katada, et al., "Magnitude and role of wall shear stress on cerebral aneurysm computational fluid dynamic study of 20 middle cerebral artery aneurysms," Stroke, vol. 35, pp. 2500-2505, 2004.