Modelling Cerebral Aneurysm Evolution

We present a fluid-solid-growth model for the evolution of a saccular cerebral aneurysm on the internal carotid sinus artery. The model utilises a realistic constitutive model of the arterial wall that accounts for the structural arrangement of collagen fibres in the medial and adventitial layers, the natural reference configurations in which the collagen fibres are recruited to load bearing and the mass of the elastin and collagenous constituents. The structural model is integrated into a patient-specific geometry of the internal carotid artery. This enables growth and remodelling (G&R) of the aneurysmal section to be explicitly linked to physiologically realistic haemodynamic stimuli. In addition, a quasi-static approach is used to obtain the geometry of the aneurysmal section at systolic and diastolic pressures, enabling G&R to be explicitly linked to the magnitude of the cyclic stretches. To our knowledge, this is the first patient-specific model of cerebral aneurysm evolution that incorporates a realistic constitutive model of the arterial wall and explicitly links G&R to the pulsatile mechanical environment. It will provide the basis for further investigating and elucidating the aetiology of the disease.