Identification of hemodynamics risk factors for the rupture of cerebral aneurysms

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K12765
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 90110:Biomedical engineering-related
• Research Institution: Nihon University
• Principal Investigator: SHIMOGONYA Yuji 日本大学, 工学部, 准教授 (30552575)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 脳動脈瘤 / 血流 / 血行力学 / 計算流体力学 / wall shear stress

Outline of Final Research Achievements

The purpose of this study was to clarify the hemodynamic factors involved in cerebral aneurysm enlargement. Numerical analysis of blood flow was performed on a realistic geometrical model created from pre-enlargement CT image data of enlarged cases and CT image data of non-enlarged cases, and various hemodynamic parameters were compared. Hemodynamic quantities before and after enlargement in the enlarged cases were also compared. The results showed that "high wall shear stress + strong disturbance" similar to that at the time of aneurysm initiation may occur in the neck region at the time of aneurysm enlargement. The results also suggested that the hemodynamic environment is completely different between aneurysm enlargement and rupture. The switch in the hemodynamic environment may be the point of divergence between a "stabilizing aneurysm" and a "rupturing aneurysm”

Free Research Field

生体流体力学

Academic Significance and Societal Importance of the Research Achievements

本研究の最終的な目標は，脳動脈瘤破裂の危険因子を同定し，破裂リスクの新しい診断法の創出を通じて臨床に貢献することである。今回の研究により，瘤増大と破裂では血行力学的環境が全く異なるということを示唆する結果が得られた。血行力学的環境が切り替わるかどうかが「安定化する瘤」と「破裂へと移行する瘤」の分岐点（すなわち，環境が切り替わった時点が破裂リスクの高い状況）である可能性がある。今回の成果を足掛かりとして，血行力学的環境が切り替わる要因を明らかにすることが今後の課題である。それを明らかにし，脳動脈瘤破裂の血行力学的なリスク評価を行えるようになれば，新しい診断法の創出に繋がると期待される。