Role of Hemodynamics in Initiation of Aneurysmal Remodeling

Hemodynamic insult has long been speculated to be a key factor in intracranial aneurysm (IA) formation,¹ but the specifics of hemodynamic insult contributing to this process are not understood. Despite other risk factors, IAs are predominantly found at locations associated with unique hemodynamic stress such as at the apices of arterial bifurcations or outer curves, prominent in high wall shear stress (WSS) and wall shear stress gradients (WSSG).² Furthermore, it appears that increased flow at these locations is required to trigger the initiation of aneurysmal remodeling.³ We have previously shown that increasing flow in the rabbit basilar artery (BA), secondary to common carotid artery (CCA) ligation, resulted in nascent aneurysm development at the basilar terminus (BT).⁴ However, it is unclear if certain hemodynamic stress thresholds must be exceeded to trigger aneurysmal remodeling, and whether sustained insult is necessary.