Recanalization and reperfusion therapies for acute ischemic stroke.

Arterial recanalization and subsequent reperfusion have extensively demonstrated the ability to restore the brain function when performed shortly after acute ischemic stroke. Experimental and human studies have consistently demonstrated that early tissue reperfusion may limit ischemic tissue enlargement, leading to a reduced infarct size and favorable clinical outcome. However, arterial recanalization does not necessarily lead to brain tissue reperfusion. Lack of reperfusion after early recanalization may be caused by multiple downstream embolization, blockage of microcirculation due to non-reflow phenomenon or rapid recruitment of ischemic tissue before recanalization resulting in non-nutritional reperfusion. In some cases, sudden tissue reperfusion may be deleterious, leading to brain blood barrier disruption and hemorrhagic transformation or massive brain edema due to the so-called 'reperfusion injury'. In spite of this, recanalization represents the powerful predictor of stroke outcome and it is being increasingly used as a surrogate efficacy measurement in thrombolytic and other revascularization trials in acute stroke. Several emerging strategies have the potential to extend cerebral reperfusion therapy to larger numbers of patients, including patients presenting beyond the current 3-hour time window. Moreover, novel reperfusion approaches may improve the efficacy and safety of thrombolysis in a larger number of stroke patients. This review highlights recent advances in reperfusion treatments for acute ischemic stroke.