ORIENTAL-MeVO
(2026)Objective
To determine whether endovascular thrombectomy improves functional outcomes in patients with acute ischemic stroke due to medium-vessel occlusion and moderate-to-severe deficits.
Study Summary
• Symptomatic intracranial hemorrhage: 4.7% thrombectomy vs 2.2% control
• 90-day mortality: 11.1% thrombectomy vs 10.2% control
• Successful reperfusion (eTICI 2b50-3) achieved in 74.4% of thrombectomy patients
Intervention
Endovascular thrombectomy (stent retrievers, aspiration, angioplasty, stents, or intraarterial thrombolysis at operator's discretion) plus standard medical management vs standard medical management alone.
Inclusion Criteria
Adults ≥18 years with pre-stroke mRS 0-2, NIHSS ≥6, presenting within 24 hours of last known well, with occlusion of M2/M3 MCA, A1/A2/A3 ACA, or P1/P2/P3 PCA; <50% ischemic involvement on imaging or mismatch ratio >1.4 with penumbra ≥10 ml.
Study Design
Arms: Endovascular thrombectomy + medical management (n=280) vs Medical management alone (n=283)
Patients per Arm: 280 vs 283
Outcome
• Symptomatic intracranial hemorrhage: 4.7% vs 2.2%
• 90-day mortality: 11.1% vs 10.2%
• Thrombectomy improved functional outcomes but at cost of higher sICH risk
Bottom Line
In patients with acute ischemic stroke due to medium-vessel occlusion and moderate-to-severe deficits (NIHSS ≥6), endovascular thrombectomy increased the likelihood of functional independence at 90 days compared with medical management alone (58.6% vs 46.6%), though at the cost of more symptomatic intracranial hemorrhage (4.7% vs 2.2%).
Major Points
- First positive randomized trial of endovascular thrombectomy for medium-vessel occlusion strokes
- Functional independence (mRS 0-2) at 90 days was significantly higher with thrombectomy (58.6% vs 46.6%, adjusted RR 1.24, 95% CI 1.07-1.44, P=0.004)
- Selective enrollment of patients with moderate-to-severe deficits (NIHSS ≥6) may explain divergence from prior neutral trials
- Symptomatic intracranial hemorrhage was more than 2-fold higher with thrombectomy (4.7% vs 2.2%)
- Mortality at 90 days was similar between groups (11.1% vs 10.2%)
- Successful reperfusion (eTICI 2b50-3) achieved in 74.4% of thrombectomy patients
- The proportional-odds assumption was violated, so prespecified dichotomized mRS 0-2 outcome was used as primary
Study Design
- Study Type
- Investigator-initiated, prospective, open-label, multicenter, randomized controlled trial with blinded outcome assessment
- Randomization
- Yes
- Blinding
- Open-label treatment with blinded outcome assessment (PROBE design)
- Sample Size
- 564
- Follow-up
- 90 days
- Centers
- 48
- Countries
- China
Primary Outcome
Definition: Functional independence (modified Rankin scale score of 0, 1, or 2) at 90 days. Originally planned as ordinal shift in mRS, but proportional-odds assumption was violated, so prespecified dichotomized outcome was used.
| Control | Intervention | HR/OR | P-value |
|---|---|---|---|
| 46.6% | 58.6% | - (1.07 to 1.44) | 0.004 |
Limitations & Criticisms
- Single-country trial conducted entirely in China — generalizability to other populations and healthcare systems may be limited
- Open-label design (only outcome assessment was blinded)
- Lower-than-expected complete reperfusion rate (only 5.8% achieved eTICI 3 on initial angiography)
- Imbalance in occlusion sites between groups (M2 more common in thrombectomy group, M3 more common in control)
- Imbalance in antiplatelet therapy use (67.1% thrombectomy vs 77.4% control)
- Higher rate of symptomatic intracranial hemorrhage requires risk-benefit discussion
- Original ordinal shift analysis could not be performed due to violation of proportional-odds assumption
Citation
N Engl J Med 2026;394:1894-904