Hemodynamic Features of Microsurgically Identified, Thin-Walled Regions of Unruptured Middle Cerebral Artery Aneurysms Characterized Using Computational Fluid Dynamics

Neurosurgery. 2020 Jun 1;86(6):851-859. doi: 10.1093/neuros/nyz311.

Abstract

Background: Thin-walled regions (TWRs) of aneurysm surfaces observed in microscopic surgery are thought to be vulnerable areas for growth and rupture of unruptured intracranial aneurysms (UIAs).

Objective: To identify hemodynamic features of TWRs of aneurysms by using computational fluid dynamics (CFD) analyses of unruptured middle cerebral artery bifurcation (MCAB) aneurysms.

Methods: Nine patients with 11 MCAB aneurysms were enrolled, and their TWRs were identified. CFD analysis was performed using 3 parameters: pressure, wall shear stress (WSS), and WSS divergence (WSSD). Each parameter was evaluated for its correspondence with TWR.

Results: Among 11 aneurysms, 15 TWRs were identified. Corresponding matches with CFD parameters (pressure, WSS, and WSSD) were 73.33, 46.67, and 86.67%, respectively.

Conclusion: WSSD, a hemodynamic parameter that accounts for both magnitude and directionality of WSS, showed the highest correspondence. High WSSD might correspond with TWR of intracranial aneurysms, which are likely high-risk areas for rupture.

Keywords: Aneurysm; Computational fluid dynamics; Thin-walled region; Wall shear stress divergence.

MeSH terms

  • Cerebral Revascularization / methods*
  • Female
  • Hemodynamics / physiology*
  • Humans
  • Hydrodynamics*
  • Imaging, Three-Dimensional / methods*
  • Intracranial Aneurysm / diagnostic imaging*
  • Intracranial Aneurysm / surgery*
  • Male
  • Middle Aged
  • Retrospective Studies
  • Stress, Mechanical