The aim of this study is to characterize the different flows present at anterior communicating artery (AcoA)
aneurysms and investigate possible associations with rupture. For that purpose, patient-specific
computational models of 26 AcoA aneurysms were constructed from 3D rotational angiography images.
Bilateral images were acquired in 15 patients who had both A1 segments of the anterior cerebral arteries
and models were created by fusing the reconstructed left and right arterial trees. Computational fluid
dynamics simulations were performed under pulsatile flow conditions. Visualizations of the flow velocity
pattern were created to classify the aneurysms into the following flow types: A) inflow from both A1
segments, B) flow jet in the parent artery splits into three secondary jets, one enters the aneurysm and the
other two are directed to the A2 segments, C) the parent artery jet splits into two secondary jets, one is
directed to one of the A2 segments and the other enters the aneurysm before being directed to the other A2
segment, and D) the parent artery jet enters the aneurysm before being directed towards the A2 segments.
The maximum wall shear stress in the aneurysm at the systolic peak (MWSS) was calculated. Most
aneurysms in group A were unruptured and had the lowest MWSS. Group B had the same number of
unruptured and ruptured aneurysms, and a low MWSS. Groups C and D had high rupture ratios, being the
average MWSS significantly higher in group C. Finally, it was found that the MWSS was higher for
ruptured aneurysms of all flow types.