In 2015, five randomized trials showed efficacy of endovascular thrombectomy over standard medical care in patients with acute ischemic stroke caused by occlusion of arteries of the proximal anterior circulation. However, sufficient recanalization (mTICI2b-3) can 't be acquired in all patients under thrombectomy. There is a lack of evidence that whether salvage intra-arterial thrombolysis is beneficial for patients with insufficient recanalization after endovascular thrombectomy. The EXTEND-IA TNK study indicated that tenecteplase before thrombectomy was associated with a higher incidence of reperfusion and better functional outcome than alteplase among patients with ischemic stroke treated within 4.5 hours after symptom onset. This study intends to explore the proportion of sufficient recanalization (2b/3) after intra-arterial tenecteplase administration in patients undergoing thrombectomy with insufficient recanalization (1/2a).

Inclusion Criteria:

1. Age ≥18 years;
2. Patients who presented with acute ischemic stroke and a large vessel occlusion in the anterior circulation and met the criteria of mechanical thrombectomy;
3. insufficient perfusion (mTICI 1/2a) after endovascular treatment;
4. The availability of informed consent.

Exclusion Criteria:

1. Sufficient recanalization (TICI 2b-3);
2. More than 3 times of thrombectomy device passes
3. Hemorrhagic stroke: cerebral hemorrhage, subarachnoid hemorrhage
4. Coagulation disorders, systematic hemorrhagic tendency, thrombocytopenia ( <100000/mm3)
5. Severe hepatic or renal dysfunction, increase in ALT or AST (more than 2 times of upper limit of normal value), increase in serum creatinine (more than 1.5 times of upper limit of normal value) or requiring dialysis
6. Severe uncontrolled hypertension (systolic blood pressure over 200mmHg or diastolic blood pressure over 110 mmHg)
7. Patients allergic to any ingredient of drugs in our study
8. Unsuitable for this clinical studies assessed by researcher