pRESET for Occlusive Stroke Treatment

To determine the safety and effectiveness of pRESET for the treatment of acute ischemic stroke within 8 hours of symptom onset (defined as time patient was last seen well) due to large vessel occlusion and to compare safety and effectiveness to the predicate device, Solitaire™ Platinum revascularization device

Inclusion criteria

• Age >/=18
• Clinical signs consistent with acute ischemic stroke
• Subject is able to be treated within 8 hours of stroke symptom onset and within 1.5 hours (90 min) from screening CT / MRI to groin puncture.
• Pre-stroke modified Rankin Score of 0 or 1
• NIHSS ≥6 at the time of enrolment
• If tPA is indicated, initiation of IV tPA should be administered as soon as possible and no later than 3.0 hours of onset of stroke symptoms (onset time is defined as the last time when the patient was witnessed to be at baseline neurologic status), with investigator verification that the subject has received/is receiving the correct IV tPA dose (0.9mg/kg) for the estimated weight.
• Expanded Thrombolysis in Cerebral Infarction (eTICI) 0-1 flow confirmed by angiography that is accessible to the mechanical thrombectomy device in the following locations:

• Intracranial internal carotid
• M1 and/or M2 segment of the MCA
• Carotid terminus
• Vertebral artery
• Basilar artery

Note: M1 segment of the MCA is defined as the arterial trunk from its origin at the ICA to the first bifurcation or trifurcation into major branches neglecting the small temporo-polar branch.

• Imaging scores as follows:

· ASPECTS score must be 6-10 on NCCT or DWI-MRI.

If automated core volume assessment software is used:

• MR diffusion-weighted imaging (DWI) ≤50cc
• Computed tomography perfusion (CTP) core ≤50 cc
• Subject is willing to conduct protocol-required follow-up visits.
• A valid completed informed consent by participant or LAR (Legally Authorized Representative)

Exclusion criteria

• Subject who has received IA-tPA prior to enrolment in the study
• Female who is pregnant or lactating or has a positive pregnancy test at time of admission.
• Rapid neurological improvement prior to study enrolment suggesting resolution of signs/symptoms of stroke
• Known serious sensitivity to radiographic contrast agents
• Known sensitivity to nickel, titanium metals, or their alloys
• Subjects already enrolled in other investigational studies that would interfere with study endpoints
• Known hereditary or acquired hemorrhagic diathesis, coagulation factor deficiency. (A subject without history or suspicion of coagulopathy does not require INR or prothrombin time lab results to be available prior to enrolment.)
• Known renal failure as defined by a serum creatinine > 2.0 mg/dl (or 176.8 μmol/l) or glomerular filtration rate (GFR) < 30.
• Subject who requires hemodialysis or peritoneal dialysis, or who has a contraindication to an angiogram for whatever reason.
• Life expectancy of less than 90 days
• Clinical presentation suggests a subarachnoid hemorrhage, even if initial CT or MRI scan is normal
• Suspicion of aortic dissection
• Subject with a comorbid disease or condition that would confound the neurological and functional evaluations or compromise survival or ability to complete follow-up assessments.
• Subject is known to currently use or has a recent history of illicit drug(s) or abuses alcohol (defined as regular or daily consumption of more than four alcoholic drinks per day).
• Known arterial condition (e.g., proximal vessel stenosis or pre-existing stent) that would prevent the device from reaching the target vessel and/or preclude safe recovery of the device
• Subject who requires balloon angioplasty or stenting of the carotid artery at the time of the index procedure
• Angiographic evidence of carotid dissection

Imaging exclusion criteria:

• CT or MRI evidence of hemorrhage on presentation
• CT or MRI evidence of mass effect or intra-cranial tumor (except small meningioma)
• CT or MRI evidence of cerebral vasculitis
• CT or MRI-DWI showing ASPECTS 0-5. Alternatively, if automated core volume assessment software is used, MRI-DWI or CTP core > 50cc.
• CT/MRI shows evidence of carotid dissection or complete cervical carotid occlusion requiring a stent
• Any imaging evidence that suggests, in the opinion of the investigator, the subject is not appropriate for mechanical thrombectomy intervention (e.g. inability to navigate to target lesion, moderate/large infarct with poor collateral circulation, etc.).
• Occlusions in multiple vascular territories (e.g., bilateral anterior circulation, or anterior/posterior circulation) as confirmed by angiography, or clinical evidence of bilateral strokes or strokes in multiple territories