Reperfusion Failure Despite Recanalization in Stroke: New Translational Evidence

Current treatment for acute ischemic stroke aims at recanalizing the occluded blood vessel to reperfuse ischemic brain tissue. Clot removal can be achieved pharmacologically with a thrombolytic drug, such as recombinant tissue plasminogen activator, or with mechanical thrombectomy. However, reopening the occluded vessel does not guarantee full tissue reperfusion, which has been referred to as reperfusion failure. When it occurs, reperfusion failure significantly attenuates the beneficial effect of recanalization therapy and severely affects functional recovery of stroke patients. The mechanisms of reperfusion failure are somewhat complex and not fully understood. Briefly, after stroke, capillaries show stalls, constriction and luminal narrowing, being crowded with neutrophils, and fibrin–platelet deposits. Furthermore, after recanalization in stroke patients, a primary clot can break, dislodge, and occlude distal arterial branches further downstream. In this review, we highlight a rodent model that allows studying the pathophysiological mechanisms underlying reperfusion failure after stroke. We also describe the vascular and intravascular changes involved in reperfusion, which may provide relevant therapeutic targets for improving treatment of stroke patients.