The primary objective of this study is to evaluate whether rescue stenting therapy can improve neurological functional outcomes after failed endovascular treatment for acute ischemic stroke caused by large vessel occlusion. The study population is divided into two groups:

Stent Placement Group: If recanalization is not achieved after 3-5 attempts of thrombectomy, direct stent placement or balloon angioplasty is performed.

Continued Thrombectomy Group: If recanalization is not achieved after 3-5 attempts of thrombectomy, at least one additional thrombectomy attempt is performed.

The primary efficacy endpoint is the proportion of patients achieving a modified Rankin Scale (mRS) score of 0-2 at 90±7 days.

The safety endpoint is the incidence of symptomatic intracranial hemorrhage within 48 hours after randomization.

Inclusion Criteria:

1. Age ≥18 years
2. Pre-stroke mRS 0-1
3. Symptoms of AIS present within 24 hours of last known well time
4. Baseline NIHSS score ≥6
5. Anterior circulation: ASPECTS ≥6; Posterior circulation: pc-ASPECTS ≥6
6. Occlusion of intracranial ICA, M1 segment of MCA, V4 segment of vertebral artery, or basilar artery
7. Clinical care team intends to perform endovascular therapy (EVT)
8. Failure to achieve recanalization (eTICI 0-1) after 3 thrombectomy attempts, including: At least one contact aspiration attempt; At least one stent retriever attempt or combined approach
9. Subject or legally authorized representative can provide informed consent

Exclusion Criteria:

1. Intracranial hemorrhage confirmed by imaging prior to randomization; or intraprocedural flat-panel CT evidence of major hemorrhage
2. Gastrointestinal or genitourinary bleeding within 30 days post-stroke onset; or major surgery within 14 days
3. Bleeding diathesis, including:Laboratory evidence of coagulopathy (PLT <100×10⁹/L, aPTT >50 sec, or INR >2.0); Direct oral anticoagulant (DOAC) use within 48 hours prior; History of heparin-induced thrombocytopenia (HIT)
4. Pregnancy or lactation at admission
5. Contraindications to:Radiographic contrast agents; Nickel, titanium, or their alloys (device-related)
6. Life expectancy <6 months
7. Pre-existing neurological/psychiatric conditions that may confound neurological assessment
8. Severe renal insufficiency:GFR <30 mL/min or Serum creatinine >220 μmol/L (2.5 mg/dL)
9. Arterial tortuosity or other vascular anomalies preventing device delivery to target vessel
10. Unlikely to complete 90-day follow-up