Cerebrovascular diseases
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Cerebrovascular diseases · Jan 2010
Review Comparative StudyRisk of aneurysm rupture at intracranial arterial bifurcations.
Aneurysms on the posterior circulation, most commonly located at the basilar top, have a higher risk of rupture than aneurysms on the anterior circulation. If hemodynamic shear stress, which has its maximum impact at the distal carina of bifurcations, explains the higher rupture rate of basilar top aneurysms, aneurysms at the top of the carotid artery should have similar rupture rates given their geometrical similarities. ⋯ Aneurysms are less frequently located on the carotid than on the basilar artery bifurcation. The proportion of ruptured carotid aneurysms is smaller than that of unruptured carotid aneurysms, suggesting a lower rupture risk for aneurysms at the carotid artery bifurcation. The anatomical geometry of the bifurcations and concomitant hemodynamic stress are considered an unlikely explanation for the higher risk of posterior circulation aneurysms.