ReStore Thrombectomy Trial for Flow Restoration in Acute Ischemic Stroke Patients

The ReStore™ Thrombectomy device restores blood flow in the neurovascular by removing thrombus in patients experiencing ischemic stroke. Patients enrolled in the ReStore Trial will be randomized to treatment with the ReStore™ Thrombectomy Device (investigational treatment) or to treatment with a commercially available thrombectomy device It is expected that the investigational treatment safety profile in terms of clinically significant procedural adverse events will be comparable to the control group.

The objective of this study is to demonstrate substantial equivalence of the ReStore™ Thrombectomy Device with the legally marketed MERCI Retrieval System. The study will evaluate safety and efficacy of the ReStore™ Thrombectomy Device in subjects diagnosed with acute ischemic stroke who require mechanical thrombectomy. All eligible patients will be enrolled and randomized to treatment with either the investigational therapy or the control therapy.

Eligibility Criteria:
Inclusion Criteria:

* Age ≥ 22 and ≤ 85 years
* Clinical signs consistent with the diagnosis of acute ischemic stroke
* Pre-stroke Modified Rankin Score ≤2
* National Institute of Health Stroke Scale (NIHSS) assessment score ≥8 and \<30
* Patient presents between 0 and 8 hours of onset of stroke symptoms
* Contraindicated for IV t-PA treatment (as specified by drug manufacturer's IFU) OR Acute ischemic stroke treated with intravenous thrombolytic therapy where vascular imaging (TCD, CTA, MRA, or angiography) shows a persistent occlusion after the end of the infusion treatment. NOTE:
* Treatment initiated within 8 hours after symptom onset (first retrieval pass made within 8 hours)
* Neurologic signs that are NOT rapidly improving (NIHSS score has NOT decreased by 4 or more points as determined prior to or at the time of treatment as compared to the initial screen;
* TIMI 0 or 1 flow in internal carotid, middle cerebral M1/M2 segments, basilar, or vertebral arteries confirmed by angiography which are accessible to the retrieval devices.
* Patient/patient legal authorized representative willing to comply with protocol requirements and return to the treatment center for all required clinical evaluations
* Patient or legally authorized representative has given informed consent, and consent is documented.

Exclusion Criteria:

* NIHSS ≥30 or comatose
* Known to be pregnant
* Serum glucose level \<50 mg/dL
* Excessive cervical arterial tortuousity that prevents placement of the retrieval devices
* Known hemorrhagic diathesis
* Patients exhibiting signs suggestive of or angiographic evidence of bilateral stroke
* Coagulation factor deficiency (or oral anticoagulation therapy with INR\>3.0)
* In receipt of heparin within 48 hours with a PTT \> 2x the lab normal
* Baseline platelets \<30,000 mm3
* Known serious sensitivity to intra-arterial radiographic contrast agents
* Severe sustained hypertension (systolic blood pressure \> 185 mmHg or diastolic \>110 mmHg)
* Baseline CT or MRI revealed significant mass effect with midline shift or greater than 1/3 of the MCA region with hypodensity (sulcal effacement and/or loss of gray-white differentiation is allowed)
* Neurologic signs that are rapidly improving at the time of treatment as measured by a decrease in NIHSS score of 4 or more points as determined prior to or at the time of treatment as compared to the initial screen
* CT or MRI evidence of hemorrhage on presentation
* CT or MRI evidence of mass effect or intracranial tumor (except small meningioma)
* Life expectancy \< 3 months
* Angiographic evidence of carotid dissection, or high grade stenosis (\> 50% stenosis of the artery proximal to the target vessel) that will prevent access to the clot, or vasculitis
* At the discretion of the investigator, patients with co-morbidities associated with a life expectancy of less than 3 months or co-morbidities that could influence the study results or make clinical follow-up difficult will be excluded.