Effect of Vascular Anatomy on the Formation of Basilar Tip Aneurysms

Abstract

Larger posterior cerebral artery angles and smaller basilar artery diameters are associated with the formation of basilar tip aneurysms. These parameters are easily measurable by the clinician and will aid in screening strategies in high-risk patients.

Does the DSA reconstruction kernel affect hemodynamic predictions in intracranial aneurysms? An analysis of geometry and blood flow variations

“…Furthermore, aneurysm neck size overestimation due to 3D RA can lead to significantly different WSS results and a different flow structure classification. Other groups reported that the vascular anatomy has the greatest influence on the development of IA and subsequent rupture,21 22 whereas other factors such as viscosity play only a minor role 23 24. However, these results are based on a small number of IAs and must therefore be considered with caution.…”

Is there an inherited anatomical conformation favoring aneurysmal formation of the anterior communicating artery?

“…It has been previously demonstrated that the geometry of the affected arteries can contribute to the formation of the IA, independent of familial contributions. 2,[6][7][8]12,15,18,39 Specifically, the anatomy of the anterior complex of the CW can create a trend toward the formation of IAs in the ACoA. 16 Indeed, IAs form preferentially at arterial bifurcations and on tight vascular curvatures (having a low radius of curvature).…”

“…However, in patients with sporadic aneurysms, the effect of specific anatomical variations within the circle of Willis (CW) on the formation of IA has been well established. 2,[6][7][8]16 The purpose of this study was to investigate specific anatomical variations within the anterior communicating artery (ACoA) complex that may be significantly associated with the presence of IAs. For this purpose we compared anatomical and structural characteristics of the ACoA complex, such as asymmetry and angle measurement, in 3 groups: patients with a familial ACoA aneurysm (FACAA), patients with a sporadic ACoA aneurysm (SACAA), and healthy first-degree relatives (HFDRs) of FACAA patients.…”

Low prevalence of fetal-type posterior cerebral artery in patients with basilar tip aneurysms

“…Kayembe et al ,16 found no increased incidence of fPCA in the aneurysm group compared with controls, but only four of the 44 aneurysms studied involved the basilar tip. More recently, Can et al ,10 found that a smaller BA diameter and a larger P1–P1 angle were associated with a higher incidence of BTA, but anatomical variants of the circle of Willis were not assessed. Campos et al ,18 identified P1 agenesis in 2.8% of 47 patients with BTA, but hypoplastic P1 segments were not assessed and no data on the prevalence of those variants in individuals without BTA were given.…”

“…Established modifiable risk factors include smoking, alcohol consumption, and hypertension,1–3 but genetic predisposition is also an important factor 2 4. Hemodynamic forces also play a major role in aneurysm formation, enlargement, and rupture, with wall shear stress and transmural pressure linked to mechanical and molecular changes,4–9 triggering focal degenerative mechanisms at the vessel wall 10. Accordingly, saccular aneurysms are most commonly located at branching points of the major arteries, where hemodynamic stress is highest 5…”