EndovaSCular TreAtment to imProve outcomEs for Medium Vessel Occlusions (ESCAPE-MeVO Trial)

Inclusion Criteria:

1. Acute ischemic stroke clinically eligible for immediate EVT

2. Age ≥18 years at the date of randomization

3. Time from onset (or last-seen-well) to randomization <12 hours

4. Disabling stroke defined as follows:

5. baseline National Institutes of Health Stroke Scale (NIHSS) score >5 at thetime of randomization

6. NIHSS 3-5 with disabling deficit (eg. hemianopia, aphasia, loss of handfunction) as determined by the attending physician in context of the patient'slife situation

7. Confirmed symptomatic and endovascularly treatable MeVO based on neurovascularnon-invasive imaging (mCTA or MRA), at one or more of the following locations: M2 orM3 segment, A2 or A3 segment, P2 or P3 segment1.

8. . Clinical deficit commensurate with MeVO occlusion location

9. . Signed informed consent, two-physician consent, or deferral of consent whereapproved

Exclusion Criteria:

8. ASPECTS ≤ 5

9. The following depend on the imaging modality of the participating site:

9a. NCCT + mCTA

• Well demarcated hypodensity in the majority of the brain parenchyma supplied by theoccluded vessel or absence of collaterals in the affected territory on the delayedphases of the mCTA OR 9b. NCCT + (m)CTA + CTP**

• Lack of core: penumbra mismatch (if the CTP is uninterpretable, e.g., due to motionartifacts, apply exclusion criteria from 9a. If single-phase CTA is performed, scorecollaterals accordingly. If NCCT + mCTA + CTP are all performed, the core: penumbramismatch criteria are sufficient for exclusion) OR 9c. MRI

• Diffusion restriction in the majority of the brain parenchyma supplied by theoccluded vessel

• if MR perfusion is performed: lack of core:penumbra mismatch 10) Any evidence ofintracranial hemorrhage on qualifying imaging 11) Patients living in a nursing homeor requiring daily nursing care or assistance with activities of daily living.

12. Patient has a major co-morbid illness, such as severe dementia, advancedcancer, advanced heart failure etc. such that they are unlikely to be able tocomplete follow-up or they are unlikely to achieve the primary outcome due tothe underlying illness (rather than the stroke or its treatment).

13. Pregnancy: female with positive urine or serum beta human chorionicgonadotropin (β-hCG) test 14) Participation in another clinical therapeuticintervention trial