Modeling Flow in Cerebral Aneurysm After Coils Embolization Treatment: A Realistic Patient-Specific Porous Model Approach

• Published in: Cardiovascular engineering and technology Vol. 14; no. 1; pp. 115 - 128
• Main Authors: Romero Bhathal, Julia, Chassagne, Fanette, Marsh, Laurel, Levitt, Michael R., Geindreau, Christian, Aliseda, Alberto
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-02-2023; Springer Nature B.V
• Subjects: Aneurysms; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedical Engineering/Biotechnology; Biomedicine; Cardiology; Computational fluid dynamics; Embolization, Therapeutic - adverse effects; Endovascular Procedures; Heterogeneity; Humans; Hydrodynamics; Image reconstruction; Intracranial Aneurysm - diagnostic imaging; Intracranial Aneurysm - therapy; Mathematical models; Original Article; Permeability; Porosity; Porous media; Synchrotrons; Coils; Porous model; Cerebral aneurysm; Computational fluid dynamics
• ISSN: 1869-408X; 1869-4098; 1869-4098
• DOI: 10.1007/s13239-022-00639-x

Purpose
Computational fluid dynamics (CFD) has been used to evaluate the efficiency of endovascular treatment in coiled cerebral aneurysms. The explicit geometry of the coil mass cannot typically be incorporated into CFD simulations since the coil mass cannot be reconstructed from clinical images due to its small size and beam hardening artifacts. The existing methods use imprecise porous medium representations. We propose a new porous model taking into account the porosity heterogeneity of the coils deployed in the aneurysm.
Methods
The porosity heterogeneity of the coil mass deployed inside two patients’ cerebral aneurysm phantoms is first quantified based on 3D X-ray synchrotron images. These images are also used to compute the permeability and the inertial factor arising in porous models. A new homogeneous porous model (porous crowns model), considering the coil’s heterogeneity, is proposed to recreate the flow within the coiled aneurysm. Finally, the validity of the model is assessed through comparisons with coil-resolved simulations.
Results
The strong porosity gradient of the coil measured close to the aneurysmal wall is well captured by the porous crowns model. The permeability and the inertial factor values involved in this model are closed to the ideal homogeneous porous model leading to a mean velocity in the aneurysmal sac similar as in the coil-resolved model.
Conclusion
The porous crowns model allows for an accurate description of the mean flow within the coiled cerebral aneurysm.