Combined clinical and computational information in complex cerebral aneurysms: Application to mirror cerebral aneurysms

Although the incidence of ruptured cerebral aneurysms is relatively small, when rupture occurs, morbidity and mortality are exceptionally high. The understanding of the pathological and physiological forces driving aneurysmal pathogenesis and progression is crucial. In this paper we analyze the occurrence of mirror cerebral aneurysms in 8 patients and speculate on the effect of haemodynamics on the localization and course of the disease. By mirror cerebral aneurysms we indicate two aneurysms in the same patient and at the same location in the cerebral vasculature but symmetrically with respect to a sagittal plane. In particular we focus on cases of mirror cerebral aneurysms where only one of the two aneurysms presented subarachnoid hemorrhage (SAH). Anatomical information is extracted from 3D rotational angiography (3DRA) images and haemodynamic information is obtained through blood flow simulation in patientspecific anatomical models. The distribution of Wall Shear Stress (WSS) and the flow patterns through the vessels and inside the aneurysms are reported. By combining clinical observations on asymmetry of the cerebral vasculature and aneurysmal shape and size with computed information on blood flow patterns we explore the causes behind a specific localization and a different outcome of disease progression.