Evaluation of Acute Endovascular Treatment in Symptomatic Isolated Cervical Internal Carotid Artery Occlusion Within 24 Hours of Last Seen Well (ETICA)

Inclusion Criteria:

• ≥18-year-old patients (no upper age limit)

• Clinical signs consistent with AIS (Acute ischemic stroke), and time from last seenwell to randomization ≤23h

• NIHSS score >5 at randomization time

• Ischemic stroke confirmed by cerebral imaging (CT: Computed Tomography orMRI:Magnetic Resonance Imaging) or normal imaging with suspected ischemic stroke

• Existence of a mismatch: If perfusion data are available (PWI/CTP), existence of acore-perfusion mismatch, suggestive of carotid hemodynamic mechanism, according tothe DEFUSE-3 criteria: mismatch volume ≥15 mL, core volume ≤70 mL, and mismatchratio ≥1.8 ; if perfusion data are not available, or non interpretable, existence ofa clinical-imaging mismatch, defined by an ASPECTS >5 (Alberta Stroke Program EarlyCT score)

• CICAO (Cervical isolated Internal Carotid Artery Occlusion) on CTA (ComputedTomography Angiography) or MRA with gadolinium, without associated visibleipsilateral large intracranial occlusion (T or L, M1, M2, A1, A2, P1, P2), <1 hbefore randomization

• Anticipated possibility to start the EVT procedure (arterial access) within 60minutes after randomization

• Pre-stroke mRS score ≤2

• Patient or patient's representative has received information about the study and hassigned and dated the appropriate Informed Consent or met the criteria for emergencyconsent, signed by the investigator

Exclusion Criteria:

• CICAO after recent (<1 month) endarterectomy

• Patient with severe or fatal co-morbidities or life expectancy <6 months that willlikely interfere with improvement or follow-up or that will render the procedureunlikely to benefit the patient

• Patient unable to come or unavailable for follow-up

• Pre-existing neurological or psychiatric disease that would confound theneurological or functional evaluations

• Seizures at stroke onset if they make the diagnosis of stroke doubtful and precludeobtaining an accurate baseline NIHSS assessment

• Suspected cerebral vascular disease (e.g., vasculitis) based on the medical historyand CTA/MRA

• Pregnancy in progress or planned during the study period, woman who is known to bepregnant or lactating at admission time

• Adult protected by law or patient under guardianship or curators

• Current participation in another investigational drug or device study

• Not affiliated to the French social security system or not beneficiary of suchsystem

• Known contrast or endovascular product life-threatening allergy

• Associated stenosis (≥50%) of the middle cerebral artery ipsilateral to the CICAO

• Chronic CICAO, defined as a known carotid occlusion (on a previous imaging exam) ≥30days before randomization or high suspicion of chronic CICAO based on medicalhistory and CT/MRI

• Tandem occlusion, defined by cervical ICA occlusion associated with intracraniallarge vessel occlusion (T- or L-shaped, M1 or M2 portions of the middle cerebralartery, A1 or A2 portions of the anterior cerebral artery, P1 or P2 portions of theposterior cerebral artery)

• Associated ipsilateral large intracranial arterial occlusion

• Prior stenting of the target ICA

• Intracranial stent implanted in the same vascular territory as the CICAO

• Sub-occlusive cervical ICA stenosis on CTA or MRA

• Suspicion of ICA occlusion starting at the petrous, cavernous or intracranialsegment with normal cervical portion on non-invasive imaging (MRA or/and CTA)

• Known absence of vascular access

• Suspicion of aortic dissection based on medical history, clinical evaluation or/andimaging

• Sub-occlusive cervical ICA stenosis on CTA or MRA

• Common carotid artery occlusion without ICA occlusion on non-invasive imaging (MRAor/and CTA)

• Evidence of intracranial hemorrhage on CT/MRI.