Tetsuo Sasaki1, Yukinari Kakizawa1, Masato Yoshino2,3, Yasuhiro Fujii4, Ikumi Yoroi4, Yozo Ichikawa1, Tetsuyoshi Horiuchi1, Kazuhiro Hongo1. 1. Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan. 2. Institute of Engineering, Academic Assembly, Shinshu University, Nagano, Japan. 3. Institute of Carbon Science and Technology, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, Japan. 4. Department of Mechanical Systems Engineering, Shinshu University, Nagano, Japan.
Abstract
BACKGROUND: Hemodynamic factors, especially wall shear stress (WSS), are generally thought to play an important role in intracranial aneurysm (IA) formation. IAs frequently occur at bifurcation apices, where the vessels are exposed to the impact of WSS. OBJECTIVE: To elucidate the relationship between bifurcation geometry and WSS for IA formation. METHODS: Twenty-one bifurcation models varying in branch angles and branch diameters were made with 3-dimensional computer-aided design software. In all models, the value of maximum WSS (WSSMAX), the area of high WSS (AREA), and the magnitude of wall shear force over AREA ($| {{{\vec{F}}_w}} |$) were investigated by the steady-flow simulation of computational fluid dynamics. RESULTS: On the basis of statistical analysis, WSSMAX tended to be high when the bifurcation angle and/or branch diameter was small. AREA and $| {{{\vec{F}}_w}} |$ significantly increase as the bifurcation and/or the branch angle became larger. CONCLUSION: The magnitude of WSS strongly correlated with bifurcation geometry. In addition to high WSS, AREA and $| {{{\vec{F}}_w}} |$ were thought to affect IA formation. Observed bifurcation geometry may predict IA formation. Large branch angles and small branch may increase the risk of IA formation.
BACKGROUND: Hemodynamic factors, especially wall shear stress (WSS), are generally thought to play an important role in intracranial aneurysm (IA) formation. IAs frequently occur at bifurcation apices, where the vessels are exposed to the impact of WSS. OBJECTIVE: To elucidate the relationship between bifurcation geometry and WSS for IA formation. METHODS: Twenty-one bifurcation models varying in branch angles and branch diameters were made with 3-dimensional computer-aided design software. In all models, the value of maximum WSS (WSSMAX), the area of high WSS (AREA), and the magnitude of wall shear force over AREA ($| {{{\vec{F}}_w}} |$) were investigated by the steady-flow simulation of computational fluid dynamics. RESULTS: On the basis of statistical analysis, WSSMAX tended to be high when the bifurcation angle and/or branch diameter was small. AREA and $| {{{\vec{F}}_w}} |$ significantly increase as the bifurcation and/or the branch angle became larger. CONCLUSION: The magnitude of WSS strongly correlated with bifurcation geometry. In addition to high WSS, AREA and $| {{{\vec{F}}_w}} |$ were thought to affect IA formation. Observed bifurcation geometry may predict IA formation. Large branch angles and small branch may increase the risk of IA formation.
Authors: Theresa A Lansdell; Courtney Fisher; Kent Simmonds; Mat J Reeves; Daniel Woo; Anne M Dorrance; Stacie L Demel Journal: Neurogenetics Date: 2019-03-27 Impact factor: 3.017
Authors: Wojciech Kaspera; Karolina Ćmiel-Smorzyk; Wojciech Wolański; Edyta Kawlewska; Anna Hebda; Marek Gzik; Piotr Ładziński Journal: Sci Rep Date: 2020-02-06 Impact factor: 4.379