ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

CHARACTERIZATION OF THE RUPTURE SITE IN INTRACRANIAL
ANEURYSMS BASED ON CFD COMPUTATIONS
P. Berg 1 , O. Beuing 2 , G. Janiga 3 , M. Neugebauer 4 , M. Skalej 5 and D. Thévenin 6
1. ABSTRACT
In case of diseased intracranial arterial walls focal or segmental dilatations may
develop, which are referred to as cerebral aneurysms. If a rupture sets in, consequences
are often devastating. In this work two patient-specific cerebral aneurysms are
investigated by means of CFD (Computational Fluid Dynamics) simulations. In both
cases a rupture occurred during the medical examination without any manipulation.
Hence, both configurations can be used in an attempt to characterize specifically the
location of rupture. Unsteady hemodynamic simulations are carried out on high-quality
block-structured grids. Besides velocity and pressure distribution, temporally averaged
wall shear stresses (AWSS) as well as the oscillatory shear index (OSI) are analyzed.
Neither elevated velocity nor pressure values are found within the area of interest.
However, an oscillating flow motion is identified that may influence the endothelial cell
layer. Increased AWSS and OSI appear mainly at the neck of the aneurysms and distal to
the bifurcations, respectively, disqualifying them as driving factors regarding a rupture
in the present configurations.
2. INTRODUCTION
Circumscript or fusiform defects in the walls of intracranial arteries may lead to focal or
segmental dilatations of intracranial vessels, which are referred to as cerebral aneurysms
[1]. Due to growing and remodeling processes a rupture can set in at any time, leading
to a sudden death or permanent disabilities depending on the amount of blood leaving
the vascular system [2,3]. Unfortunately, the cause of a rupture is not well understood
yet. A better understanding would be extremely important for an improved treatment of
detected aneurysms and to decrease the risk of rupture.
Although high resolution images and time-dependent velocity measurements are
possible, e.g., by means of 7-Tesla magnetic resonance tomography (MRT) [4], the
complex interactions in blood flow cannot be revealed experimentally so far. This work
focuses on the computational investigation (CFD: Computational Fluid Dynamics) of
1 PhD student, Department of Fluid Dynamics and Technical Flows, University of Magdeburg,
Universitaetsplatz 2, 39106 Magdeburg, Germany
2 MD, Department of Neuroradiology, University Hospital of Magdeburg, Leipziger Straße 44, 39120
Magdeburg, Germany
3 PhD, Department of Fluid Dynamics and Technical Flows, University of Magdeburg, Universitaetsplatz
2, 39106 Magdeburg, Germany
4 PhD student, Department of Simulation and Graphics, University of Magdeburg, Universitaetsplatz 2,
39106 Magdeburg, Germany
5 Professor and Director, MD, Department of Neuroradiology, University Hospital of Magdeburg,
Leipziger Straße 44, 39120 Magdeburg, Germany
6 Professor and Director, PhD, Department of Fluid Dynamics and Technical Flows, University of
Magdeburg, Universitaetsplatz 2, 39106 Magdeburg, Germany