An assessment of how the anterior cerebral artery anatomy impacts ACoA aneurysm formation based on CFD analysis

Abstract

Objective

The aim of this study was to identify independent anatomic, morphologic and hemodynamic features of the ACoA (anterior communicating artery) complex that serve as risk factors for the occurrence of ACoA aneurysms.

Methods

Fifteen consecutive patients with 15 ACoA aneurysms were included. Computational fluid dynamics (CFD) simulations based on patient-specific models were carried out using 3D time-of-flight magnetic resonance angiography (3D-TOF-MRA) images. A reverse reconstruction technique was used to generate a pre-aneurysm vessel anatomy. Geometric parameters and hemodynamic changes were compared and evaluated.

Results

The overall prevalence of symmetric, dysplastic, and absent A1 segments were 53.3%, 26.7%, and 20%. The mean wall shear stress (WSS) of the absent group (AG) was significantly higher than that of the symmetric group (SG) and dysplastic group (DG). The absolute mean A1 artery flow rate (410.2 ± 88 versus 439.4 ± 101 mL/min; p = .45) of the aneurysm side was similar between the SG and DG but significantly higher in the AG (528.1 ± 77 mL/min; p < .05). The A1-A2 angles of the aneurysm side showed no significant differences among the 3 groups (p = .32). However, the mean A1-A2 angle on the aneurysm side was smaller than the contralateral A1-A2 angle (101.9 ± 9.1˚ versus 120.3 ± 7.7˚; p <.05). A regression analysis demonstrated that high WSS was significantly associated with a large A1-A2 ratio (R²=0.52; p <.05).

Conclusions

ACoA aneurysms are a high-WSS pathology. Severe flow impingement and the anatomic vasculature structures play a role in triggering the occurrence of ACoA aneurysms.

Keywords:

• Cerebral aneurysm
• anterior communicating artery
• computational fluid dynamics
• aneurysm model

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of our institutional review board and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in the study.

Author contributions

1. Geng Zhou and Weidong Liu: Acquisition of data, analysis and interpretation of data and drafting of the manuscript.

2. Yueqi Zhu and Minghua Li: Study concept and design, critical revision of the manuscript for important intellectual content and study supervision.

3. Haitao Lu and Wenquan Gu: acquisition of data and statistical analysis.

4. Ming Su and Yong Feng: acquisition of data.

5. Binjie Qin: critical revision of the manuscript for important intellectual content.

Disclosure statement

We declare there is no conflict of interest in this study.

Additional information

Funding

This work was supported by Yueqi Zhu grants: Shanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant Support (No.20152528); and by Weidong Liu grants: Outstanding Clinical Discipline Project of Shanghai Pudong (grant no. PWYgy2018-04) and National Institutes of Health (grant no. NS076491).