Millipede AspiRation for Revascularization in Stroke (MARRS) Study

Prior treatment

• Known previous stroke within the past 3 months.
• Subject currently participating in or has previously participated in another trial involving an investigational device or drug within 30 days of enrollment.
• Life expectancy of less than 6 months prior to stroke onset.
• For all patients, severe sustained hypertension with SBP \>220 mmHg and/or DBP \>120 mmHg; for patients treated with thrombolytic therapy, sustained hypertension despite treatment with SBP \>185 mmHg and/or DBP \> 110 mmHg.
• Initially treated with intra-arterial thrombolytics or a different neurothrombectomy device before use of the Millipede System.
• Known arterial condition in a proximal vessel that requires treatment or prevents access to the site of occlusion or safe recovery of the investigational device (for example, severe stenosis, complete occlusion in the cervical ICA, tandem occlusion).
• Evidence of multiple vascular occlusions (e.g., bilateral anterior circulation, anterior/posterior circulation, concurrent occlusions in the anterior cerebral artery (ACA) and MCA, other concurrent ipsilateral occlusions in the same or different territories).

Other illness

• In the Investigator's opinion, any known comorbidity (including COVID-19) that may complicate treatment or prevent improvement or follow-up.
• Known history of severe contrast allergy.
• Pre-existing neurological or psychiatric disease that would confound the neurological or functional evaluation.
• Ongoing seizure due to stroke.
• Clinical symptoms of bilateral stroke or stroke in multiple territories.
• Known history of cerebral vasculitis.
• Evidence of active systemic infection (e.g. septicemia). Exceptions: common cold, hepatitis B virus (HBV), hepatitis C virus (HCV).
• Evidence of current intracranial hemorrhage on imaging.
• Known cancer with metastases.

Lab values

• Known history of coagulation factor deficiency or oral anti-coagulant therapy with an International Normalized Ratio (INR) of more than 3.0.
• Known history of treatment with heparin within 48 hours with a Partial Thromboplastin Time (PTT) more than two times the laboratory normal.
• Known history of treatment with a direct thrombin inhibitor within 48 hours with a PTT more than 1.5 times the laboratory normal.
• Known glucose level\< 50 mg/dl (2.78 mmol/L) or \> 400 mg/dl (22.20 mmol/L).
• Known platelet count \<50,000/µL.
• Renal failure with serum creatinine ≥3 mg/dL or Glomerular Filtration Rate (GFR) \<30 mL/min.

Other

• Females who are known to be pregnant or breastfeeding.
• Known cocaine use at time of treatment.
• Clinical history, past imaging or clinical judgement suggest that the intracranial occlusion is chronic.
• Any known hemorrhagic or coagulation deficiency.
• Significant mass effect with midline shift.
• Suspicion or evidence of aortic dissection, septic embolus, or bacterial endocarditis.
• Evidence of dissection in the extracranial or intracranial cerebral arteries.
• Excessive arterial tortuosity that may preclude device placement as determined by CTA/Magnetic Resonance Angiography (MRA) and/or conventional angiography.
• CT or MRI showing mass effect or intracranial tumor (apart from small meningioma, ≤ 2 cm in diameter).
• Known aneurysm at or near the target treatment segment.
• Angiographic evidence of known or suspected underlying intracranial vasculopathy or atherosclerotic lesions responsible for the target occlusion

• Subjects aged ≥ 18 and ≤ 85 years.
• Pre-stroke mRS score of ≤ 1.
• Baseline NIHSS score of ≥ 6.
• A new focal disabling neurologic deficit consistent with acute cerebral ischemia.
• Evidence of a large vessel occlusion of the intracranial ICA (including T or L occlusions), the M1 or M2 segments of the MCA, the intracranial vertebral artery, or the basilar artery on magnetic resonance angiography (MRA) or computed tomography angiography (CTA).
• Subject belongs to one of the following subgroups:
  • Subject is ineligible for thrombolytic therapy, OR
  • Subject is eligible for thrombolytic therapy and thrombolytic therapy was administered without delay and per current practice guidelines.
• For strokes in the anterior circulation, the following imaging criteria should be met:
  • Magnetic Resonance Imaging (MRI) criterion: volume of diffusion restriction visually assessed as ≤ 50 mL, or Alberta Stroke Program Early CT Score (ASPECTS) 6-10; OR
  • Computed Tomography (CT) criterion: Alberta Stroke Program Early CT Score (ASPECTS) 6-10 on baseline CT or Computed Tomography Angiography (CTA)- source images, or volume of significantly lowered relative Cerebral Blood Flow (rCBF) \<30% (volume of ≤ 50 mL if CT perfusion is performed).
• For strokes in the posterior circulation, the following imaging criterion should be met: pcASPECTS score 8 to 10 on baseline CT, CTA-source images, or Diffusion- Weighted Imaging (DWI) MRI.
• The interventionalist estimates that arterial puncture can be completed within 8 hours of onset/last known well.
• Informed consent obtained in accordance with the applicable country-specific regulations and as approved by the IRB/ REC.
• Angiographic confirmation of a single large vessel occlusion (mTICI of 0-1) of the intracranial ICA (including T or L occlusions), the M1 or M2 segments of the MCA, the intracranial vertebral artery, or the basilar artery that is accessible to the Millipede System.