The Netherlands Organisation for Health Research and Development, Sanquin Blood Supply, Chest Heart and Stroke Scotland, French Ministry of Health.

Background and Purpose-The ability to discriminate between ruptured and unruptured cerebral aneurysms on a morphological basis may be useful in clinical risk stratification. The objective was to evaluate the importance of inflow-angle (IA), the angle separating parent vessel and aneurysm dome main axes. Methods-IA, maximal dimension, height-width ratio, and dome-neck aspect ratio were evaluated in sidewall-type aneurysms with respect to rupture status in a cohort of 116 aneurysms in 102 patients. Computational fluid dynamic analysis was performed in an idealized model with variational analysis of the effect of IA on intra-aneurysmal hemodynamics. Results-Univariate analysis identified IA as significantly more obtuse in the ruptured subset (124.9°Ϯ26.5°versus105.8°Ϯ18.5°, Pϭ0.0001); similarly, maximal dimension, height-width ratio, and dome-neck aspect ratio were significantly greater in the ruptured subset; multivariate logistic regression identified only IA (Pϭ0.0158) and height-width ratio (Pϭ0.0017), but not maximal dimension or dome-neck aspect ratio, as independent discriminants of rupture status. Computational fluid dynamic analysis showed increasing IA leading to deeper migration of the flow recirculation zone into the aneurysm with higher peak flow velocities and a greater transmission of kinetic energy into the distal portion of the dome. Increasing IA resulted in higher inflow velocity and greater wall shear stress magnitude and spatial gradients in both the inflow zone and dome. Conclusions-Inflow-angle is a significant discriminant of rupture status in sidewall-type aneurysms and is associated with higher energy transmission to the dome. These results support inclusion of IA in future prospective aneurysm rupture risk assessment trials. (Stroke.

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BACKGROUND AND PURPOSE:Wide-neck bifurcating aneurysms are increasingly treated with intracranial stent-assisted coiling by using shape-memory alloy microstents. We sought to investigate the short-and long-term effects of intracranial stent implantation on the geometry and angular conformation of the stent-coiled vascular bifurcation.

Retrospective morphological and hemodynamic analysis point to a dichotomy between sidewall and bifurcation aneurysms with respect to performance of shape and size parameters in identifying rupture status, suggesting the need for aneurysm type-based analyses in future studies. The current most commonly used clinical risk assessment metric, D(max), was found to be of no value in differentiating between ruptured and unruptured bifurcation aneurysms.

Stent-induced angular remodeling significantly altered bifurcation apex hemodynamics in a favorable direction by blunting apical pressure and inducing the narrowing and migration of the FIZ, a novel response to intracranial stenting that should be added to intimal hyperplasia and flow diversion.

Y-configuration stent coiling induced immediate and, more significantly, a previously undefined delayed cerebrovascular remodeling. This progressive stent-induced angular remodeling alters perianeurysmal hemodynamics, independent of the flow-diverting properties of stent struts, thus shifting the balance of hemodynamic forces affecting aneurysm development and evolution.

Background and Purpose-Whether intracerebral hemorrhage (ICH) survivors should restart antithrombotic drugs is unknown.We analyzed the frequency of restarting antithrombotic drugs in ICH survivors who had taken prophylactic antithrombotic drugs in atrial fibrillation or after thromboembolic disease in 5 cohorts and explored factors associated with doing so. Methods-We compared the characteristics and proportions of patients taking antithrombotic drugs at ICH onset and discharge in 4 hospital-based cohorts (Lille, France, n=542; Utrecht, The Netherlands, n=389; multicenter Clinical Relevance of Microbleeds in Stroke-2 (CROMIS-2) ICH, United Kingdom, n=667; and Amsterdam, The Netherlands, n=403) and 1 community-based study (Lothian, Scotland, n=137), using bivariate analyses. We sought characteristics associated with restarting using bivariate and multivariable logistic regression analyses. Results-A total of 942 (44%) patients with ICH took antithrombotic drugs at hospital admission (no difference between cohorts).Antithrombotic drugs were restarted in 96 (20%) of the 469 survivors who had taken antithrombotic drugs for secondary prevention or atrial fibrillation, but this proportion differed when stratified by the cohort of origin (Lille, 18%; Utrecht, 45%; Lothian, 15%; CROMIS-2 ICH, 11%; Amsterdam, 20%; P<0.001) and by type of antithrombotic drug pre-ICH (14% in patients with previous antiplatelet drugs versus 26% in patients with previous vitamin K antagonists and 41% in patients with both drugs; P<0.001). We did not find other consistent, independent associations with restarting antithrombotic drugs. Conclusions-The variation in clinical practice and lack of consistent associations with restarting antithrombotic drugs after ICH reflect current knowledge and support the need for randomized controlled trials to resolve this dilemma.