Current status of computational fluid dynamics for cerebral aneurysms: the clinician's perspective.

The ultimate management goal for unruptured intracranial aneurysms is to select the aneurysms at risk of rupture and treat them. Computational fluid dynamics (CFD) utilizes mechanical engineering principles to explicate what occurs in tubes (vessels) and bulges (aneurysms). CFD parameters have been related to the biological processes that occur in the aneurysm wall, and models have been developed to predict the risk of aneurysm rupture. A PubMed search from 1 January 1970 to 30 November 2010 was carried out using the keywords "computational fluid dynamics" AND "cerebral aneurysm". References were also reviewed for relevant articles. All relevant articles were then reviewed by a vascular neurosurgeon, who found that the hemodynamic parameters of wall shear stress (WSS), WSS gradient, inflow jet, impingement zone, and aneurysm inflow-angle (IA) lack the predictive values required for clinical practice. CFD study can now be simulated and reproduced in a simple and fast analysis of steady, non-pulsatile flow with phase contrast magnetic resonance-derived volumetric inflow rate but the key question of whether a patient-specific CFD model can predict the rupture risk of unruptured intracranial aneurysms remains to be determined in future studies incorporating multivariate analysis. CFD models will become available for routine clinical practice as the computational power of computers further improves.