To determine if the Trevo Retriever is as good or better than the Merci Retriever in restoring blood flow to the brain of a patient experiencing an acute ischemic stroke in a large vessel.

The TREVO 2 protocol was designed to assess the safety and effectiveness of the Trevo Retriever device and determine if it is substantially equivalent to the predicate Merci Retriever. The trial utilized a Primary Effectiveness Endpoint of revascularization and a composite Primary Safety Endpoint that included procedure-related serious adverse events occurring within 24 hours of the procedure. Subjects who presented to enrolling centers with large ischemic strokes were screened for eligibility in the study. If a subject met eligibility criteria, then Informed Consent was obtained prior to commencing the angiogram. If all inclusion/exclusion criteria were confirmed, including the angiographic criteria, then the subject was randomized.The Primary Effectiveness Endpoint was successful revascularization of the target occlusion, using the TICI score. Success was determined by the central Core Lab.The Primary Safety Endpoint is a composite endpoint, described in the protocol as the "Incidence of procedure-related serious adverse events (PRSAEs) through 24 hours post procedure (-6/+12 hours) defined as: vascular perforation or intramural arterial dissection, symptomatic ICH, embolization to a previously uninvolved territory, access site complication requiring surgical repair or blood transfusion, intra-procedural mortality, device failure (in vivo breakage), or any other complications judged by the Clinical Events Committee (CEC) to be related to the procedure."

Key Inclusion Criteria:

• Patient presenting with clinical signs and symptoms consistent with a diagnosis of Acute Ischemic Stroke, and:

  • Patient has failed IV t-PA therapy Or
  • Patient is contraindicated for IV t-PA administration

• NIHSS 8 < NIHSS < 29

• Anticipated life expectancy of at least 6 months

• No significant pre-stroke disability (mRS < 1)

• Written informed consent to participate given by patient or legal representative

• Angiographic confirmation of a persistent large vessel occlusion in the internal carotid, middle cerebral (M1 and/or M2 segments), basilar and/or vertebral arteries

• Treatable within 8 hours of symptom onset, defined as the first pass being made with the assigned study device

Key Exclusion Criteria:

• Abnormal blood pressure and/or blood coagulation lab values
• Pregnancy
• Patient participating in another investigational drug or device study
• More than 1/3 of MCA or equivalent in non-MCA territory
• Baseline evidence of significant mass effect with midline shift, or hemorrhage, or intracranial tumor
• Bilateral stroke

Each subject was followed for 90 days; The study period was 1 year.

A study specific AE classification system was used to categorize Site Reported AEs and SAEs.

The study used an independent clinical events committee, CT and MRI imaging core laboratory, a separate angiography core laboratory, and an independent data safety and monitoring board (DSMB) to ensure appropriate oversight and analysis.