No-reflow phenomenon after revascularization in acute ischemic stroke: Achilles' heel of the neurointerventionalist?

In 2015, several clinical trials demonstrated the efficacy of endovascular reperfusion therapies (EVT) in stroke patients with large vessel occlusion, which had changed stroke treatment guidelines and clinical practice all over the world. However, despite substantial recanalization, about half of the patients obtain a poor functional outcome at 3 months after endovascular treatment. The difference between the high recanalization rate of cerebral vessels and the low recovery rate of good clinical function has become a pain for neurointerventionalists! Alberta stroke program early CT score (ASPECTS), direct arrival, previous thrombolysis, time from onset to recanalization < 6 h, and recanalization status, etc. are certainly the reasons for this outcome. But we may have overlooked an important issue, that recanalization of blood vessels does not mean reperfusion of tissues. The phenomenon of poor tissue perfusion after recanalization is called no-reflow phenomenon (NRP). Coronary NRP has become an important predictor of clinical prognosis for acute coronary occlusion after percutaneous coronary intervention (PCI). In the past nearly half century, interventional cardiologists have done a lot of researches on the pathogenesis, diagnosis and treatment of NRP, which effectively improve the clinical efficacy of coronary PCI. When neurointerventionalists are actively carrying out endovascular treatment for acute ischemic stroke, should they actively pay more attention to NRP?