Using computational fluid dynamics to predict clinical outcome of aneurysms treated by flow diverters

![CDATA[Purpose: The haemodynamic profiles of aneurysms treated by flow diverters (FD) were analysed with computational fluid dynamics (CFD) to determine the profiles associated with successful and failed treatments. Materials & Methods: Using ANSYS software, patient-specific CFD were used to simulate haemodynamic profiles including the presence of jet flow, energy loss, volume flow and wall shear stress in 4 successful occlusions of aneurysms and 4 failed cases after FD deployment. A successful case was defined as occlusion within 6 months. Failed cases include rupture post treatment and failure to occlude within 6 months. In the 4 failed cases, haemodynamic profiles were examined again after a hypothetical second intervention. This involved replacing the failed FD with a hypothetical optimally deployed FD or simulated placement of a second FD within the first. Results: Where successful occlusions were achieved, a marked obliteration of jet flow was observed. Flow entering the aneurysm sac was diverted via the centre of the FD and exited smoothly into the parent arteries. These observations were supplemented by a reduction in the other haemodynamic profiles. In failed cases, the strong jet flow persisted without reduction of the other parameters. Aneurysm neck geometry significantly influenced the efficacy of the FD. Conclusion: Haemodynamic indices, as calculated using CFD techniques, have close correlation with FD treatment outcome. CFD could be potentially useful as a planning tool for neurointerventionists by simulating an optimised flow diverter deployment strategy prior to the procedure and evaluating post-treatment outcome.]]