Efficacy of Rescue Stenting/Angioplasty After Failed Thrombectomy for Acute Large Intracranial Vascular Occlusion

• Stent placement (Procedure): For patients who fail thrombectomy, perform stent placement.
• Continued Thrombectomy (Procedure): For patients with failed thrombectomy, perform at least one additional thrombectomy attempt
• balloon angioplasty (Procedure): For patients who fail thrombectomy, perform balloon angioplasty.

Primary outcomes

• Proportion of patients with mRS 0-2 [90±7 days]: Proportion of patients with Modified Rankin Scale (mRS) 0-2, Modified Rankin Scale（0-6）, A lower MRS score indicates better functional status for the patient.

Secondary outcomes

• Change in NIHSS score from baseline [36±12 hours post-randomization]: Change in National Institute of Health stroke scale score from baseline.The NIH Stroke Scale (NIHSS) score ranges from 0 to 42 points, with lower scores indicating better neurological function
• Vascular recanalization rate assessed by CT/MR angiography [at 36±12 hours post-randomization]: Vascular recanalization rate assessed by CT/MR angiography
• Change in infarct volume [at 7±3 days post-randomization or discharge (whichever comes first)]: Change in infarct volume
• Distribution of mRS scores [7±3 days/discharge and 90±7 days post-randomization]: Modified Rankin Scale（0-6）, A lower MRS score indicates better functional status for the patient.
• Proportion of patients achieving mRS 0-1 [90±7 days]: Proportion of patients achieving mRS 0-1
• Incidence of rescue therapy [90±7 days]: Incidence of rescue therapy
• EQ-5D-5L utility score [90±7 days]: The EuroQol 5-Dimension 5-Level Utility Score (EQ-5D-5L utility score) ranges from -0.594 to 1.000 (Chinese value set), assessing health-related quality of life, with higher scores indicating better health status.
• Probability of symptomatic intracranial hemorrhage [48 hours]: Probability of symptomatic intracranial hemorrhage
• All-cause mortality [90±7 days post-randomization]: All-cause mortality
• Probability of any intracranial hemorrhage (per Heidelberg criteria) [48 hours post-randomization]: Probability of any intracranial hemorrhage (per Heidelberg criteria)

Sex: All, ages: 18 Years to any

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