Impacts of futile reperfusion and reperfusion injury in acute ischemic stroke

Abstract

Acute ischemic stroke (AIS) remains to be a challenging cerebrovascular disease. The mainstay of AIS management is endovascular reperfusion therapy, including thrombectomy and thrombolysis. However, ineffective (futile) reperfusion (FR) or reperfusion injury (RI) can be seen in a significant number of patients undergoing reperfusion strategy. In this article, we discuss two clinically relevant concepts known as "time window" and "tissue window" that can impact the clinical outcome of reperfusion therapy. We also explore patient risk factors, leading to FR and RI as well as an emerging concept of "no-reflow phenomenon" seen in ineffective reperfusion. These fundamental concepts provide insight into the clinical management of AIS patients and provide references for future research.

Keywords: Endovascular reperfusion therapy; ineffective (futile) reperfusion; no-reflow phenomenon; thrombectomy; thrombolysis; time window; tissue window.

Figure 1

This diagram illustrates the therapeutic pathways and outcomes for ischemic stroke. At the onset of stroke, two primary interventions, the thrombectomy and thrombolysis, can be considered, while both aimed at recanalization of the occluded blood vessel. If recanalization is effective, it leads to reperfusion, restoring blood flow to the affected brain region. A successful reperfusion can result in neuroprotection and functional recovery. However, if recanalization is not effective, it can lead to three possible outcomes: (1) Reperfusion that may occur but too late does not rescue brain issue; and/or (2) Reperfusion occurs but causes reperfusion injury, leading to additional brain damage; (3) Persistence of no blood flow resulting in brain injury