Inclusion & Exclusion Criteria for POSITIVE Trial

Inclusion Criteria

  • Age 18 to 80 years (i.e., candidates must have had their 18th birthday but not had their 81st birthday)
  • NIHSS ≥ 8 at the time of neuroimaging
  • Presenting or persistent symptoms within 12 hours of when groin puncture can be obtained
  • Neuroimaging demonstrates large vessel proximal occlusion (distal ICA through MCA M1 bifurcation)
  • The operator feels that the stroke can be appropriately treated with traditional endovascular techniques (endovascular thrombectomy without adjunctive devices such as stents).
  • Pre-event Modified Rankin Scale score 0-1
  • Consenting requirements met according to local IRB

Exclusion Criteria

  • Patient eligible for IV-tPA therapy
  • Rapidly improving neurologic examination
  • Absence of large vessel occlusion on non-invasive imaging
  • Known or suspected pre-existing (chronic) large vessel occlusion in the symptomatic territory
  • Absence of an associated large penumbra as defined by physiologic imaging according to standard of practice at the participating institution
  • Any intracranial hemorrhage in the past 90 days
  • Known irreversible bleeding disorder
  • Known hereditary or acquired hemorrhagic diathesis, coagulation factor deficiency; or oral anticoagulant therapy with INR > 2.5 or institutionally equivalent prothrombin time of 2.5 times normal
  • Platelet count < 100 x 103 cells/mm3 or known platelet dysfunction
  • Inability to tolerate, clinically documented evidence in medical history of adverse reaction or contraindication to medications used in treatment of the stroke
  • Contraindication to CT and MRI (i.e., iodine contrast allergy or other condition that prohibits imaging from either CT or MRI)
  • Known allergy to contrast used in angiography that cannot be medically controlled
  • Relative contraindication to angiography (e.g., serum creatinine > 2.5 mg/dL)
  • Women who are currently pregnant or breastfeeding [Women of childbearing potential must have a negative pregnancy test prior to the study procedure (either serum or urine.)]
  • Evidence of active infection (indicated by fever at or higher than 99.9 F, and/or open draining wound) at the time of randomization
  • Current use of cocaine or other vasoactive substance
  • Any comorbid disease or condition expected to compromise survival or ability to complete follow-up assessments through 90 days
  • Patients who lack the necessary mental capacity to participate or are unwilling or unable to comply with the protocol's follow up appointment schedule (based on the investigator’s judgment)
  • Current participation in another interventional (drug, device, etc.) research project

Head CT or MRI Scan Exclusion Criteria

  • Presence of blood on imaging (subarachnoid hemorrhage, intracerebral hemorrhage, etc.)
  • High density lesion consistent with hemorrhage of any degree
  • Significant mass effect with midline shift
  • Large (more than 1/3 of the middle cerebral artery) regions of clear hypodensity on the baseline CT scan or ASPECTS of < 7. Sulcal effacement and/or loss of grey-white differentiation alone are not contraindications for treatment.