Abstract WP48: Antegrade Flow Across Intravascular Thrombus On 4-dimensional CTA Predicts Early Vessel Recanalization After Thrombolysis

Abstract

Introduction In acute stroke patients with large vessel occlusion, demonstration of antegrade flow across thrombus on catheter angiography has been associated with higher rates of vessel recanalization after intra-arterial thrombolysis. 4-dimensional CT angiography (4-dimensional CTA) obtained from a perfusion CT exam has recently been used for non-invasive detection of antegrade flow across intracranial thrombus. We sought to determine whether antegrade flow on 4-dimensional CTA may predict early vessel recanalization after intravenous thrombolysis. Methods: From a prospectively collected database of acute stroke patients undergoing endovascular treatment, we identified patients with the following inclusion criteria: (1) anterior circulation vessel occlusion, (2) intravenous thrombolysis (“bridging lysis”) and (3) availability of thin-section 4-dimensional CTA reconstructed from a volume perfusion CT scan. 4-dimensional CTA was reviewed for antegrade flow traversing the occlusion site. Digital subtraction angiograms (DSA) obtained at the beginning of the endovascular procedure were assessed for early partial or complete recanalization after bridging thrombolysis. Results: 67 patients met the inclusion criteria. On 4-dimensional CTA, there was evidence of antegrade flow in 12 of 67 patients (17.9 %). Patients with and without antegrade flow had similar mean age (75±10 vs. 71±14 years; p=0.188), median presenting NIHSS (15.5 [range 8-26] vs. 17 [6-26]; p=0.249), mean time from symptom onset to i.v. thrombolysis (176±147 vs. 136±84; p=0.209) and mean time from i.v.thrombolysis to DSA (79±25 vs. 89±30 minutes; p=0.265). Early partial or complete recanalization on DSA was seen in 6 patients (9%) and was significantly more likely in patients with antegrade flow (4/12, 33.3%) versus those without (2/55, 3.6%; p=0.008 according to Fisher’s exact test). Conclusion: The finding of antegrade flow across thrombus on 4-dimensional CTA is associated with an increased rate of early recanalization after intravenous thrombolysis.