Association of Concomitant Intracranial Atherosclerotic Stenosis with Collateral Status in Patients with Emergent Large Vessel Occlusion

Abstract

BACKGROUND: Concomitant atherosclerotic stenoses are commonly encountered in emergent large vessel occlusion. This study attempted to prove whether or not the pattern of atherosclerotic stenosis other than symptomatic occlusion is associated with pretreatment collateral status among patients with emergent large vessel occlusion. METHODS: The study included 115 patients with middle cerebral artery territory infarct within 6 hours of stroke onset who were considered for endovascular revascularization therapy. All patients underwent pretreatment conventional computed tomography angiography using a 128-detector high-definition computed tomography scanner. Based on maximum intensity projection images, <= 50% filling of the occluded territory was considered to indicate poor collaterals, whereas >50% filling was considered to indicate good collaterals. Finding of >50% stenosis on computed tomography angiography was considered significant, and the stenosis patterns were classified into intracranial atherosclerotic stenosis and extracranial atherosclerotic stenosis according to the location of the stenosis. RESULTS: All patients had symptomatic M1 (47.8%), M2 (20.0%), or internal carotid artery (32.2%) occlusion. There were 44 patients with poor collaterals (38.3%) and 71 patients with good collaterals (61.7%). Univariate analysis revealed that poor collateral status was associated with advanced age (>= 65 years), hypertension, high National Institutes of Health Stroke Scale score, symptomatic internal carotid artery occlusion, and concomitant atherosclerotic stenosis. Multivariate analysis showed that poor collateral circulation was associated with concomitant intracranial atherosclerotic stenosis and symptomatic internal carotid artery occlusion (vs. a more distal occlusion). CONCLUSIONS: Concomitant intracranial atherosclerotic stenosis other than symptomatic occlusion might be a crucial factor associated with pretreatment collateral status among patients with emergent large vessel occlusion.