Impaired Clearance of Emboli (Washout) Is an Important Link Between Hypoperfusion, Embolism, and Ischemic Stroke

Hypoperfusion and embolism often coexist and their pathophysiological features are interactive. Arterial lumenal narrowing and endothelial abnormalities stimulate clot formation and subsequent embolization. Reduced perfusion limits the ability of the bloodstream to clear or wash out emboli and microemboli and reduces available blood flow to regions rendered ischemic by emboli that block supply arteries. The brain border zones are a favored destination for microemboli that are not cleared. We posit that impaired washout is an important but neglected concept that intertwines hypoperfusion, embolization, and brain infarction.