Laura P Westphal1, Niklas Lohaus2, Sebastian Winklhofer2, Christian Manzolini1, Ulrike Held3, Klaus Steigmiller3, Janne M Hamann1, Mohamad El Amki1, Tomas Dobrocky4, Leonidas D Panos5, Johannes Kaesmacher4,6, Urs Fischer5, Mirjam R Heldner5, Andreas R Luft1, Jan Gralla4, Marcel Arnold5, Roland Wiest4, Susanne Wegener1. 1. Department of Neurology, Clinical Neuroscience Center, University Hospital Zurich and University of Zurich, Zurich, Switzerland. 2. Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich and University of Zurich, Zurich, Switzerland. 3. Department of Biostatistics, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland. 4. Department of Diagnostic and Interventional Neuroradiology, University Hospital Berne and University of Berne, Berne, Switzerland. 5. Department of Neurology, University Hospital Berne and University of Berne, Berne, Switzerland. 6. Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Berne and University of Berne, Berne, Switzerland.
Abstract
BACKGROUND: An incomplete circle of Willis (CoW) has been associated with a higher risk of stroke and might affect collateral flow in large vessel occlusion (LVO) stroke. We aimed to investigate the distribution of CoW variants in a LVO stroke and transient ischemic attack (TIA) cohort and analyze their impact on 3-month functional outcome. METHODS: CoW anatomy was assessed with time-of-flight magnetic resonance angiography (TOF-MRA) in 193 stroke patients with acute middle cerebral artery (MCA)-M1-occlusion receiving endovascular treatment (EVT) and 73 TIA patients without LVO. The main CoW variants were categorized into four vascular models of presumed collateral flow via the CoW. RESULTS: 82.4% (n = 159) of stroke and 72.6% (n = 53) of TIA patients had an incomplete CoW. Most variants affected the posterior circulation (stroke: 77.2%, n = 149; TIA: 58.9%, n = 43; p = 0.004). Initial stroke severity defined by the National Institutes of Health Stroke Scale (NIHSS) on admission was similar for patients with and without CoW variants. CoW integrity did not differ between groups with favorable (modified Rankin Scale [mRS]): 0-2) and unfavorable (mRS: 3-6) 3-month outcome. However, we found trends towards a higher mortality in patients with any type of CoW variant (p = 0.08) and a higher frequency of incomplete CoW among patients dying within 3 months after stroke onset (p = 0.119). In a logistic regression analysis adjusted for the potential confounders age, sex and atrial fibrillation, neither the vascular models nor anterior or posterior variants were independently associated with outcome. CONCLUSION: Our data provide no evidence for an association of CoW variants with clinical outcome in LVO stroke patients receiving EVT.
BACKGROUND: An incomplete circle of Willis (CoW) has been associated with a higher risk of stroke and might affect collateral flow in large vessel occlusion (LVO) stroke. We aimed to investigate the distribution of CoW variants in a LVO stroke and transient ischemic attack (TIA) cohort and analyze their impact on 3-month functional outcome. METHODS:CoW anatomy was assessed with time-of-flight magnetic resonance angiography (TOF-MRA) in 193 strokepatients with acute middle cerebral artery (MCA)-M1-occlusion receiving endovascular treatment (EVT) and 73 TIA patients without LVO. The main CoW variants were categorized into four vascular models of presumed collateral flow via the CoW. RESULTS: 82.4% (n = 159) of stroke and 72.6% (n = 53) of TIA patients had an incomplete CoW. Most variants affected the posterior circulation (stroke: 77.2%, n = 149; TIA: 58.9%, n = 43; p = 0.004). Initial stroke severity defined by the National Institutes of Health Stroke Scale (NIHSS) on admission was similar for patients with and without CoW variants. CoW integrity did not differ between groups with favorable (modified Rankin Scale [mRS]): 0-2) and unfavorable (mRS: 3-6) 3-month outcome. However, we found trends towards a higher mortality in patients with any type of CoW variant (p = 0.08) and a higher frequency of incomplete CoW among patients dying within 3 months after stroke onset (p = 0.119). In a logistic regression analysis adjusted for the potential confounders age, sex and atrial fibrillation, neither the vascular models nor anterior or posterior variants were independently associated with outcome. CONCLUSION: Our data provide no evidence for an association of CoW variants with clinical outcome in LVO strokepatients receiving EVT.