Vascular variations associated with intracranial aneurysms

Abstract

The rate of vascular variations in patients with aneurysms was 57.8%. Arterial hypoplasia and aplasia were the most common variations. ACS was the most common region that variations were located in; they were mostly detected on the right side. Coexistence of ACoA aneurysm was higher than PCoA and MCA aneurysms. In the PCS variations group, PCoA aneurysms were the most common aneurysms that accompanying the variation and multiple variations were more common than in the other two groups. The variations in MCS were most common in males.

The geometry of the circle of willis anatomical variants as a potential cerebrovascular risk factor

“…This can also cause a higher rate of aneurysmal bleeding in patients with anatomical variations (26,31). Asymmetrical A1 and PCoA have been reported to be associated to ACoA and PCoA aneurysms, respectively (31). Moreover, we found that the bifurcations presenting the most imbalanced geometry, such as the carotid bifurcation, the A1-A2 junction, or the PCA-PCoA junction, correspond to the most frequent localization of aneurysms and atherosclerosis (25,29).…”

“…One exception was a study by Gunnal et al, who found that asymmetry was more frequent in the PCoA (38%) followed by A1 (31%) and P1 (22%) (15), which is consistent with our findings. conducted on a series of aneurysm patients reported statistically significant correlations between the aneurysm rates and the presence of anatomical variations in the ACoA, PCoA, and MCA (31). Bourcier et al found that aneurysm patients, with or without a family history of aneurysms, presented a significant difference in the angle between the A1 and A2 segments on the aneurysmal side compared to the contralateral side, which is not observed in healthy individuals (4).…”

“…Prolonged exposure to wall shear stress induces adaptive responses in the endothelial cells, which favor the atherogenesis and degeneration of the arterial wall (29). This can also cause a higher rate of aneurysmal bleeding in patients with anatomical variations (26,31). Asymmetrical A1 and PCoA have been reported to be associated to ACoA and PCoA aneurysms, respectively (31).…”

Anatomical variations of anterior circulation in the brains of patients with and without intracranial aneurysm

“…However, there is limited Anatomical variations of anterior circulation data about this relationship in the literature. Orakdogen M et al showed that MCA variation rate and aneurysm coexistence showed no statistically significant difference in any localization (4).…”

Letter regarding the article entitled: ‘Anatomical Variations of Anterior Circulation in the Brains of Patients with and without Intracranial Aneurysm’

“…I also could not understand the rationale of its (presence of vascular variations) importance in the planning of aneurysm treatment? _____________________________________________________________________________________________________________________________ For instance, in a distinct study, Orakdogen et al also suggested that awareness of the cerebral vascular variations would guide choosing and applying treatment modalities, and increase the success rate in managing the patients (5). However, they based their hypothesis on their results of the significant association between the hypoplasia of A1 and AcoA aneurysms; the tendency of more frequent presence of colocalized cerebral variations in bleeding aneurysm cases according to non-bleeding aneurysm cases.…”