WOLF - Feasibility Neurothrombectomy Study in Acute Ischemic Stroke Patients

This study is being conducted as a feasibility clinical investigation to collect safety and technical performance data of the WOLF Thrombectomy Device for the removal of thrombus in the neurovasculature.

This study has been designed as a prospective, non-randomized, multi-center, feasibility clinical investigation to evaluate the safety and device technical performance of the WOLF Thrombectomy Device in removing thrombus from an occluded large intracranial vessel(s) in patients with acute ischemic stroke. The device may be used alone or as an adjunct to intravenous tissue plasminogen activator (tPA) and/or to other traditional, thrombectomy modalities.

Eligibility Criteria:
Inclusion Criteria:

1. Male or female subjects age ≥18 years (no upper limit).
2. NIHSS \> 6 at the time of baseline neuro imaging.
3. Endovascular treatment intended to be initiated within 60 minutes of qualifying neuroimaging and intended vessel recanalization within 90 minutes of qualifying neuroimaging.
4. Stroke symptom onset within 24hrs of when groin puncture can be obtained.
5. Anterior and posterior circulation large vessel occlusion as confirmed through neuro imaging (CT/CTA/mCTA/MRI/MRA).
6. Neurovascular imaging (CTA/mCTA and or MRA) must include the aortic arch, cervical vessels and intracranial circulation.
7. Advanced neurovascular imaging is required for patients when groin puncture can be obtained after 6 hours and before 24 hours (multiphase CTA, CT Perfusion or perfusion diffusion imaging).
8. The occlusion is located in a proximal intracranial artery (carotid artery, M1 segment of the MCA, or proximal M2 divisions) of the anterior circulation for patients after 6 hours and before 24 hours.
9. There is imaging and clinical evidence of small core and large areas at risk, defined in the previous trials (DAWN \& DEFUSE 3) as either:

   i. NIHSS ≥10 and either 0-21 ml core infarct (≥80 years old) or 0-31 ml core infarct (\<80 years old), or NIHSS≥20 and 31 to \<51ml core infarct and \<80 years old (DAWN trial criteria).

   OR ii. Ischemic core volume is \< 70 ml, mismatch ratio is \>/= 1.8 and mismatch volume\* is \>/= 15 ml (DEFUSE 3 trial criteria).
10. Pre-stroke disability limited to patients with mRS ≤ 2.
11. Written informed consent to participate given by subject or legal / authorized representative per local ethics committee requirements.

Exclusion Criteria:

1. Female subject is known to be pregnant.
2. Absence of large vessel occlusion on neuro imaging.
3. Presence of existing or preexisting large vessel infarction.
4. Angiographic evidence of excessive arterial tortuosity or access that precludes the WOLF device from reaching the thrombus.
5. Known hemorrhagic diathesis, coagulation factor deficiency, or oral anticoagulant therapy with INR \>2.5.
6. Patient has a known hypersensitivity to contrast media.
7. Medical reasons the procedure cannot be performed (i.e. patient is experiencing active, uncontrolled bleeding, etc.)
8. Subject is known to be currently enrolled in another investigational trial that could interfere with the endpoint analysis of this trial.
9. ASPECT \< 5 or \> 1/3 MCA vascular territory compromised as evidenced by CT or MRI.
10. Significant mass effect and mid-line shift.
11. Any evidence of intracranial hemorrhage on imaging.
12. For posterior circulation large vessel occlusion evidence of completed significant brain stem infarction.
13. Posterior circulation after 6 hours.
14. Patients are known to have severe psychiatric disorders, substance abuse, or other reason for being unable to follow trial follow-up instructions.
15. Subject has a known significant concomitant illness with a life expectancy of \<6 months.
16. Subject has a known allergy to nickel.
17. Subject has a known history of severe intracranial atherosclerotic disease (ICAD).
18. Subject is unlikely to be able and willing to comply with site standard medical follow up to 90 days.