Intracranial aneurismal pulsatility as a new individual criterion for rupture risk evaluation: Biomechanical and numerical approach (IRRAs project).

Mathieu Sanchez (1, 2) , Omer Ecker (3) , Dominique Ambard (1, 2) , Franck Jourdan (1, 2) , Franck Nicoud (4) , Simon Mendez (4) , J. Lejeune (5) , L. Thines (6) , H. Dufour (7, 8) , H. Brunel (9) , P. Machi (3) , K. Lobotesis (3) , Alain Bonafé (10) , Vincent Costalat (3)

1 LMGC - Laboratoire de Mécanique et Génie Civil
2 BIOTIC - Biomécanique des Interactions et de l'Organisation des Tissus et des Cellules
3 CHU Montpellier
4 I3M - Institut de Mathématiques et de Modélisation de Montpellier
5 CHRU Lille - Centre Hospitalier Régional Universitaire [CHU Lille]
6 Service d'explorations fonctionnelles respiratoires [Lille]
7 CRN2M - Centre de recherche en neurobiologie - neurophysiologie de Marseille
8 Neurologie, maladies neuro-musculaires [Hôpital de la Timone - APHM]
9 CHU Marseille
10 Service de Neuroradiologie

This study was designed to highlight by means of numerical simulations, the correlation between aneurism sac pulsatility and the risk of rupture through the mechanical properties of the wall. In accordance to previous work suggesting a correlation between the risk of rupture and the material properties of cerebral aneurysms, twelve fluid-structure interaction (FSI) computations were performed on 12 "patient-specific" cases, corresponding to typical shapes and locations of cerebral aneurysms. The variations of the aneurismal volume during the cardiac cycle (3V) are compared using wall material characteristics of either degraded and non-degraded tissues. Aneurysms were located on 7 different arteries: Middle Cerebral Artery (4), Anterior Cerebral Artery (3), Internal Carotid Artery (1), Vertebral Artery (1), Ophthalmic Artery (1) and Basilar Artery (1). Aneurysms presented different shapes (uniform or multi-lobulated) and diastolic volumes (from 18 to 392 mm3). The pulsatility (3V/V) was significantly larger for a soft aneurismal material (average of 26 %) than for a stiff material (average of 4 %). The difference between 3V, for each condition, was statistically significant: p = 0.005. The difference in aneurismal pulsatility as highlighted in this work might be a relevant patientspecific predictor of aneurysm risk of rupture.

Mots clés: cerebral aneurysms; risk of rupture; volume variation; computational cardiovascular biomechanics

Domaines: Biomécanique [physics.med-ph]; Biomécanique [physics.med-ph]

Mathieu Sanchez, Omer Ecker, Dominique Ambard, Franck Jourdan, Franck Nicoud, et al.. Intracranial aneurismal pulsatility as a new individual criterion for rupture risk evaluation: Biomechanical and numerical approach (IRRAs project).. American Journal of Neuroradiology, 2014, 35 (9), pp.1765-1771. ⟨10.3174/ajnr.A3949⟩. ⟨hal-00910141⟩