Histological Composition and the Origin of the Thrombus

See related article, p 2206 Between one third and one half of strokes will have no known cause following thorough diagnostic evaluation.1 This complicates effective secondary stroke prevention. In fact, a recent stroke classification validation approach has shown that etiologic classification systems for stroke subtype have between 0.61 (poor) to 0.71 (fair) area under the receiver operating characteristic curve for stroke recurrence within 90 days.1 In light of recent trials showing effective mechanical thrombectomy with complete or near complete removal of the embolus in most cases of emergent large vessel occlusion,2–5 an opportunity has arisen for sensitive and specific assays of the removed clot to determine stroke cause.With expanding interest in the endovascular treatment of stroke, more research emphasis has been placed on the imaging, composition, and mechanical characteristics of the clots causing large vessel occlusions. Early work attempted to compare clot composition with imaging characteristics and examine correlations to treatment response (both intravenous thrombolysis and mechanical thrombectomy).6–9 Although we …