Abstract DP305: Impact of Multidimensional Histological Clot Composition on the Selection of First Line Technique and Angiographic Outcomes During Mechanical Thrombectomy: A Comprehensive Systematic Review and Meta-Analysis

Background: Histological clot composition has emerged as a potential determinant of mechanical thrombectomy (MT) efficacy, influencing both angiographic and procedural outcomes. However, the relationship between specific clot constituents and the success of first-line techniques and reperfusion remains incompletely understood. Methods: The search strategy, extracted elements, and analysis plan were pre-specified and registered with PROSPERO (CRD420251110596). Pooled mean differences in red blood cell (RBC) and fibrin/platelet (F/P) content under random-effects models were analyzed for angiographic recanalization and procedural efficiency comparing non-first-pass effect (non-FPE) vs. FPE based on the Thrombolysis in Cerebral Infarction (TICI) scale. Additional analyses examined RBC content in clots retrieved via aspiration versus stent retriever (SR)/combined technique, and procedure time differences between RBC-rich and F/P-rich clots. For studies reporting medians and interquartile ranges, Wan’s method was used to estimate means and standard deviations. Results: Fifty studies were included, either reporting on clot composition or length. Compared to clots with TICI