Recommendations for accurate numerical blood flow simulations of stented intracranial aneurysms

Abstract The number of scientific publications dealing with stented intracranial aneurysms is rapidly increasing. Powerful computational facilities are now available; an accurate computational modeling of hemodynamics in patient-specific configurations is, however, still being sought. Furthermore, there is still no general agreement on the quantities that should be computed and on the most adequate analysis for intervention support. In this article, the accurate representation of patient geometry is first discussed, involving successive improvements. Concerning the second step, the mesh required for the numerical simulation is especially challenging when deploying a stent with very fine wire structures. Third, the description of the fluid properties is a major challenge. Finally, a founded quantitative analysis of the simulation results is obviously needed to support interventional decisions. In the present work, an attempt has been made to review the most important steps for a high-quality computational fluid dynamics computation of virtually stented intracranial aneurysms. In consequence, this leads to concrete recommendations, whereby the obtained results are not discussed for their medical relevance but for the evaluation of their quality. This investigation might hopefully be helpful for further studies considering stent deployment in patient-specific geometries, in particular regarding the generation of the most appropriate computational model.

[1]  A. Valencia,et al.  Blood flow dynamics in patient-specific cerebral aneurysm models: the relationship between wall shear stress and aneurysm area index. , 2008, Medical engineering & physics.

[2]  J. Mocco,et al.  Hemodynamic–Morphologic Discriminants for Intracranial Aneurysm Rupture , 2011, Stroke.

[3]  H. Meng,et al.  Effects of arterial geometry on aneurysm growth: three-dimensional computational fluid dynamics study. , 2004, Journal of neurosurgery.

[4]  Alejandro F. Frangi,et al.  Computational Hemodynamics in Cerebral Aneurysms: The Effects of Modeled Versus Measured Boundary Conditions , 2010, Annals of Biomedical Engineering.

[5]  N. Stergiopulos,et al.  Intracranial Stents Being Modeled as a Porous Medium: Flow Simulation in Stented Cerebral Aneurysms , 2011, Annals of Biomedical Engineering.

[6]  Gábor Janiga,et al.  Impact of stents and flow diverters on hemodynamics in idealized aneurysm models. , 2011, Journal of biomechanical engineering.

[7]  Alejandro F. Frangi,et al.  How Do Coil Configuration and Packing Density Influence Intra-Aneurysmal Hemodynamics? , 2011, American Journal of Neuroradiology.

[8]  D F Kallmes,et al.  The Woven EndoBridge: A New Aneurysm Occlusion Device , 2011, American Journal of Neuroradiology.

[9]  A. Wakhloo,et al.  Efficacy and current limitations of intravascular stents for intracranial internal carotid, vertebral, and basilar artery aneurysms. , 1999, Journal of neurosurgery.

[10]  van de Fn Frans Vosse,et al.  The influence of the non-Newtonian properties of blood on the flow in large arteries: unsteady flow in a 90° curved tube , 1999 .

[11]  Rainald Löhner,et al.  Applications of patient‐specific CFD in medicine and life sciences , 2003 .

[12]  C. Putman,et al.  Quantitative Characterization of the Hemodynamic Environment in Ruptured and Unruptured Brain Aneurysms , 2010, American Journal of Neuroradiology.

[13]  K. Takakura,et al.  Hemodynamic study of the anterior communicating artery. , 1996, Stroke.

[14]  Bernhard Preim,et al.  Virtual stenting using real patient data , 2009 .

[15]  João Reis,et al.  [Flow diverters devices for treatment of intra-cranial aneurysms--six months follow-up results]. , 2012, Acta medica portuguesa.

[16]  Joachim Schöberl,et al.  NETGEN An advancing front 2D/3D-mesh generator based on abstract rules , 1997 .

[17]  C. Putman,et al.  Hemodynamics of Cerebral Aneurysms. , 2009, Annual review of fluid mechanics.

[18]  Philipp Berg,et al.  Instationäre Strömungssimulationen und Auswertung von Blutströmungen in zerebralen Aneurysmen mit Stent , 2011, CURAC.

[19]  David A. Steinman,et al.  Robust and objective decomposition and mapping of bifurcating vessels , 2004, IEEE Transactions on Medical Imaging.

[20]  Bernhard Preim,et al.  Implicit vessel surface reconstruction for visualization and CFD simulation , 2008, International Journal of Computer Assisted Radiology and Surgery.

[21]  C B Majoie,et al.  A Flow-Diverting Stent Is Not a Pressure-Diverting Stent , 2013, American Journal of Neuroradiology.

[22]  Bernhard Preim,et al.  Generierung qualitativ hochwertiger Modelle für die Simulation von Bluttfluss in zerebralen Aneurysmen , 2008, SimVis.

[23]  Chang-Woo Ryu,et al.  Analysis of aneurysm rupture in relation to the geometric indices: aspect ratio, volume, and volume-to-neck ratio , 2011, Neuroradiology.

[24]  Gábor Janiga,et al.  Experimental validation of numerical simulations on a cerebral aneurysm phantom model. , 2012, Interventional medicine & applied science.

[25]  David R. White,et al.  Mesh‐based geometry , 2003 .

[26]  Sang Woo Ha,et al.  Clinical Analysis of Giant Intracranial Aneurysms with Endovascular Embolization , 2012, Journal of cerebrovascular and endovascular neurosurgery.

[27]  J. Mocco,et al.  MORPHOLOGY PARAMETERS FOR INTRACRANIAL ANEURYSM RUPTURE RISK ASSESSMENT , 2008, Neurosurgery.

[28]  Xi-yun Lu,et al.  Numerical investigation of the non-Newtonian pulsatile blood flow in a bifurcation model with a non-planar branch. , 2006, Journal of biomechanics.

[29]  E. Scrivano,et al.  Blood-Flow Characteristics in a Terminal Basilar Tip Aneurysm Prior to Its Fatal Rupture , 2010, American Journal of Neuroradiology.

[30]  Prahlad G. Menon,et al.  Variability of computational fluid dynamics solutions for pressure and flow in a giant aneurysm: the ASME 2012 Summer Bioengineering Conference CFD Challenge. , 2013, Journal of biomechanical engineering.

[31]  Hui Meng,et al.  Comparison of Two Stents in Modifying Cerebral Aneurysm Hemodynamics , 2008, Annals of Biomedical Engineering.

[32]  D. Liepsch,et al.  Flow in tubes and arteries--a comparison. , 1986, Biorheology.

[33]  C. Putman,et al.  Aneurysm Rupture Following Treatment with Flow-Diverting Stents: Computational Hemodynamics Analysis of Treatment , 2010, American Journal of Neuroradiology.

[34]  Hui Meng,et al.  Validation of CFD simulations of cerebral aneurysms with implication of geometric variations. , 2006, Journal of biomechanical engineering.

[35]  Kazuo Tanishita,et al.  Intra-aneurysmal hemodynamic alterations by a self-expandable intracranial stent and flow diversion stent: high intra-aneurysmal pressure remains regardless of flow velocity reduction , 2012, Journal of NeuroInterventional Surgery.

[36]  A C Burleson,et al.  Identification of Quantifiable Hemodynamic Factors in the Assessment of Cerebral Aneurysm Behavior On behalf of the Subcommittee on Biorheology of the Scientific and Standardization Committee of the ISTH , 1996, Thrombosis and Haemostasis.

[37]  Christian Rössl,et al.  Realistic virtual intracranial stenting and computational fluid dynamics for treatment analysis. , 2013, Journal of biomechanics.

[38]  Alejandro F Frangi,et al.  Reproducibility of haemodynamical simulations in a subject-specific stented aneurysm model--a report on the Virtual Intracranial Stenting Challenge 2007. , 2008, Journal of biomechanics.

[39]  Xi-yun Lu,et al.  Numerical investigation of the non-Newtonian blood flow in a bifurcation model with a non-planar branch. , 2004, Journal of biomechanics.

[40]  Alejandro F Frangi,et al.  Deployment of self-expandable stents in aneurysmatic cerebral vessels: comparison of different computational approaches for interventional planning , 2012, Computer methods in biomechanics and biomedical engineering.

[41]  Kazuo Tanishita,et al.  Mechanical design of an intracranial stent for treating cerebral aneurysms. , 2010, Medical engineering & physics.

[42]  A. Wakhloo,et al.  Stents for intracranial aneurysms: the beginning of a new endovascular era? , 1998, Neurosurgery.

[43]  Joachim Sch NETGEN An advancing front 2D/3D-mesh generator based on abstract rules , 1997 .

[44]  T. M. Liou,et al.  Pulsatile flows in a lateral aneurysm anchored on a stented and curved parent vessel , 2004 .

[45]  F Viñuela,et al.  Wall Shear Stress Distribution Inside Growing Cerebral Aneurysm , 2011, American Journal of Neuroradiology.

[46]  Rainald Löhner,et al.  Simulation of intracranial aneurysm stenting: Techniques and challenges , 2009 .

[47]  Philipp Berg,et al.  Detailed Comparison Of Numerical Flow Predictions In Cerebral Aneurysms Using Different CFD Software , 2012 .