Abstract WP40: “Good” Angiographic Collateral Circulation Correlates With Lower Dwi Infarct Volumes In Acute Ischemic Stroke

Abstract

Background and purpose Large artery occlusion leads to ischemic stroke which volume is influenced by time from symptom onset. This effect is modulated by several factors, including the presence and degree of collateral circulation. We analyze the correlation between a standard angiographic collateral grading system and DWI infarct volumes. Methods We reviewed a prospectively collected retrospective database of ischemic stroke patients admitted between august of 2006 and december of 2011. We included patients with anterior circulation acute ischemic stroke presenting within 8 hours from symptom onset with large vessel occlusion, who underwent pre-treatment MRI and endovascular therapy. DWI infarct volumes were measured by region of interest. ASITN collateral grading system was used and grouped into “good collaterals” for grades 3 and 4, and “poor collaterals” for grades 0, 1 and 2. JMP statistical software was utilized. Results 152 patients (71 (46.7%) male, mean age: 68±15 years;) were included in the initial analysis. We identified 49 patients who had angiographic collateral circulation grading. Seven patients had ASITN collateral grade 0 with mean infarct volume of 27.6 cc, 25 had collateral grade of 1 with mean infarct volume of 27.9 cc, 10 had collateral grade of 2 with mean infarct volume of 23.4 cc, 5 had collateral grade of 3 with mean infarct volume of 6.3 cc, and 2 had collateral grade of 4 with mean infarct volume of 14.6 cc. Forty two patients had “poor collaterals” with a mean infarct volume of 26.8 cc. Seven patients had “good collaterals” with mean infarct volume of 8.7 cc. When comparing the infarct volumes between these two groups, the difference was statistically significant (p=0.017). Conclusions In anterior circulation acute ischemic stroke, “good” angiographic collateral circulation defined as ASITN grading system of 3 or 4, correlates with lower infarct volumes on presentation.