1.What is acute intra-arterial thrombolysis? The microcatheter is introduced into the occlusion site (cerebral thrombosis, cerebral tethering), and the thrombolytic drugs (rt-PA, urokinase) are used for super-selective thrombolysis to open the blood vessel and unblock the blood flow. 2.What patients need intra-arterial thrombolysis in the acute stage? Indications for carotid system ①Age below 80 years old. ②There is obvious neurological dysfunction, and it is gradually aggravated for more than 1h. ③CT indicates no fresh infarct formation, and external cerebral hemorrhage or other obvious intracranial disorders are excluded. ④The onset was within 6 h. Indications for vertebrobasilar artery system ①Age below 80 years old. ②There is obvious neurological dysfunction, and the gradual aggravation lasts for more than 1 h. ③CT indicates that there is no fresh infarct formation in the brainstem and cerebellum, and external cerebral hemorrhage or other obvious intracranial disorders are excluded. ④Incurrence within 36-72 hours. 3.Which patients cannot be treated with acute intra-arterial thrombolysis? ①Clinical symptoms tend to improve significantly. ②There is a tendency of intracranial or other organs bleeding. ③History of intracranial or other surgical trauma within 2 months. ④Important organ dysfunction or failure. ⑤Systolic blood pressure >180 mmHg, or diastolic blood pressure >110 mmHg before treatment.