The ANGEL-MeVO-TNK is a multicentered, prospective, randomized, open label, blinded endpoint (PROBE) phase III trial. A total of 488 AIS patients (age ≥18 years) with acute MeVO-AIS (occlusion of the M2/M3, the A1/A2/A3, the P1/P2/P3, and with baseline NIHSS score \>5 or disabling stroke with NIHSS score 3-5 \[such as neurological deficits in motor strength, language, vision, etc\]), will be enrolled. Patients fulfilling all the inclusion criteria and none of the exclusion criteria will be randomized 1:1 into the IA TNK group or the control group after offering informed content.
* The IA TNK group：1) If the patient has not received IVT, IA TNK will be administered as a slow, continuous infusion for super-selective contact thrombolysis in a stepwise manner: an initial dose of 0.0625 mg/kg with a duration of 15 minutes. A repeat angiographic assessment will then be performed; if recanalization is not achieved, an additional dose of 0.0625 mg/kg will be administered over a further 15 minutes (maximum dose 12.5 mg) .
2\) If the patient has received IVT, intra-arterial TNK will be administered as a slow infusion for super-selective contact thrombolysis at a dose of 0.0625 mg/kg (maximum dose 6.25 mg) with a duration of 15 minutes.
* The control group will be given standard medical management.
The study consists of four visits including the day of randomization, 48±12 hours after randomization, and 90±7 days after randomization. Demographic information, symptoms and signs, laboratory test, neuro-imaging assessment neurological function rating scale will be recorded during the program.
The primary outcome is the modified Rankin Scale (mRS) score of 0 to 1 at 90±7 days after onset. The primary safety outcome is the incidence of sICH within 48±12 hours after randomization (ECASS III).