Abstract WP43: Anti-Coagulation Therapy Prior to Mechanical Thrombectomy is Associated With Reduced Procedure Time and Low Proportion of Fibrin in Retrieved Thrombus

Introduction: Very few studies have investigated the relationship between the histopathology of the retrieved thrombus by mechanical thrombectomy for large vessel occlusion and anti-coagulation agents before mechanical thrombectomy. A study in vitro showed that clots of patients with anti-coagulation agents were dissolved easily compared to those of patients with aspirin. Hypothesis: Anti-coagulation therapy prior to mechanical thrombectomy is associated with reduced procedure time and low proportion of fibrin in retrieved thrombus. Methods: All retrieved thrombus was stained with hematoxylin-eosin. Embolic debris underwent quantitative analysis to quantify three main components: red blood cells, white blood cells and fibrin, by color based segmentation. Patients were assingned to receive either mechanical thrombectomy with anti-coagulation agents (AC-MT group) or mechanical thrombectomy alone (MT group). Considering influence by stroke etiology, patients with non-cardioembolism were excluded. Results: From August 2015 to Dec 2018, 226 consecutive patients were treated in our hospital by MT for acute large vessel occlusion. Histopathologic analysis of retrieved thrombus from 119 patients with acute stroke. 92 patients with cardioembolism were included. Patients were assigned to AC-MT group (n=35) or MT group (n=57). Clinical backgrounds were not significantly different. PT-INR was higher in AC-MT group. (1.32 vs 1.06; p<0.01) The proportion of patients with recombinant tissue plasminogen activator was not significantly different (26% vs 43%; p=0.12). AC-MT group had shorter puncture to recanalization time (median 38 vs 54 minutes; p<0.01) and tendency to reduce number of maneuvers [median 2 (range 1-4) vs 2 (range 1-6); p=0.06]. AC-MT group had lower proportion of fibrin in retrieved thrombus (44.3% vs 77.3%, p<0.01). Conclusion: Anti-coagulation therapy prior to mechanical thrombectomy is associated with reduced procedure time and low proportion of fibrin in retrieved thrombus.