Abstract WP75: Enhancement of Disturbed Flow is Involved in Recanalization After Complete Endovascular Coil Embolization of Internal Carotid Artery-Posterior Communicating Artery Aneurysms

Abstract

Background and purpose: Although it is thought that hemodynamics is closely involved in recanalization after endovascular coil embolization of cerebral aneurysms, details are still not clear. Using computational flow dynamic (CFD) analysis, the aim of this study was to identify hemodynamic predictors specific to recanalization after complete coil embolization. Methods: We used patient-specific arterial geometries of 14 internal carotid artery-posterior communicating artery (ICPC) aneurysms after coil embolization. Pulsatile blood flow was simulated using ANSYS-CFX, based on the Navier-Stokes equations for incompressible fluid. As the pulsatile inlet boundary condition, we used a typical flow velocity waveform of internal carotid artery that was scaled based on the patient-specific mean velocity. In order to eliminate the influence due to aneurysm size between both groups, multivariate logistic regression analysis was performed using aneurysm size and each hemodynamic metric as independent variables to find hemodynamic predictors for recanalization after coil embolization. Results: With a follow-up of >1 year, 6 aneurysms were recanalized, and 8 cases were stable. Significant hemodynamic risk factors specific to recanalization were high values of metrics in association with disturbed flow, i.e. oscillatory shear index (OSI) [odds ratio (OR), 0.00115; 95% confidence interval (CI), 0.00102-0.00144; p = 0.017] and normalized transverse WSS (NtransWSS) (OR, 0.00103; 95%CI, 0.0010-0.00179; p = 0.043), but not flow rate of parent artery, aneurysmal mean velocity, or WSS magnitude-based metrics, including WSS and normalized WSS. Conclusions: These data suggest that enhanced disturbed flow plays a central role in recanalization after complete coil embolization of ICPC aneurysms. Imaging examinations at shorter intervals may be necessary if strong disturbed flow is observed in the aneurysm before surgery.