Abstract 138: Thrombus Composition Is Associated With First Pass Recanalization

Introduction: Our objective is to identify thrombus composition associated with first pass recanalization (FPR) in mechanical thrombectomy (MT). Methods: Intracranial thrombi obtained in MT were divided in two equal parts. One part was analyzed with anatomopathological studies to quantify fibrin, red-blood cell( Hematoxilin & Eosin) and platelets( cd61 Immunohistochemical staining ) , the other part was analyzed by flow cytometry to quantify leukocyte populations (granulocytes, lymphocytes and monocytes) and their relative proportions . FPR were defined as ≥ mTICI 2b after first pass in MT. Thrombi composition, baseline variables (demographics, previos use of antiplatelets or anticoagulants, blood pressure and blood glucose at hospital arrival ) etiology, intravenous fibrinolysis, ASPECTS score and first attempt thrombectomy devices: direct aspiration, stent retriever or combinations were compared between FPR and Non-FPR groups. Results: Fifty percent (38/76) of the cases analyzed obtained FPR. There were no differences in baseline variables , etiology, Aspects score, previous use of fibrinolysis or type of device used for MT. The thrombi obtained with FPR presented higher proportion of red blood cells (33.64% vs 18.16% p = 0.048) and lymphocytes (10.07% vs 4.43% p = 0.042) and lower proportion of platelets (61, 48% vs 67.26% p = 0.042) in comparison to non-FPR group. The proportion of platelets was an independent marker of FPR (OR 0.97; CI 0.95-0.99). There was an inverse correlation between the proportion of platelets and lymphocytes (rho -0.44, p <0.001). Conclusion: Platelets proportion in intracranial thrombus is an independent marker of first pass recanalization. Inverse relationship between lymphocytes and platelets may be a target for future reperfusion treatments