Please select the eligibility criteria that correspond to the clinical trial below.
Title: Thrombectomy REvascularization of Large Vessel Occlusions in Acute Ischemic Stroke (TREVO 2)
Brief Summary: 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.


Options:
A: Inclusion Criteria:

1. Subject or subject's legally authorized representative has signed and dated an Informed Consent Form
2. Age ≥ 18 and \< 85
3. Clinical signs consistent with acute ischemic stroke
4. Thrombolysis in Cerebral Infarction (TICI) 0 or TICI 1 flow in the proximal anterior intracranial vasculature (M1 or M2 of Middle Cerebral Artery (MCA), Internal Carotid Artery (ICA) intracranial, Internal Carotid Artery (ICA) terminal)
5. Presentation within 8 hours of stroke onset according to local stroke protocol
6. If stroke presentation within 4.5 hours, one of these conditions can be met:

   * Bridging protocol (starting intravenous and continuing with intra-arterial) (Up to maximum 0.9 mg/kg)
   * Failed intravenous thrombolysis
   * Direct Intra-arterial treatment (according to institution guidelines)
7. Subject is willing to conduct follow-up visits.
8. National Institutes of Health Stroke Scale (NIHSS) ≥ 8 and ≤ 30
9. Modified Rankin Scale (mRS) ≤ 2 prior to stroke onset

Exclusion Criteria:

1. Females who are pregnant or lactating
2. Known serious sensitivity to radiographic contrast agents
3. Neurological signs that are rapidly improving prior to or at time of treatment
4. Current participation in another investigational drug or device study
5. Life expectancy of less than 90 days
6. National Institutes of Health Stroke Scale (NIHSS) \> 30 or coma
7. Uncontrolled hypertension defined as systolic blood pressure \> 185 or diastolic blood pressure \> 110 that cannot be controlled except with continuous parenteral antihypertensive medication
8. Use of warfarin anticoagulation with International Normalised Ratio (INR) \> 3.0
9. Platelet count \< 30,000
10. Glucose \< 400 mg/dL
11. Previous stroke within 30 days
12. Time of symptom onset unknown
13. Seizure at the onset of stroke
14. Myocardial infarction or infection (sepsis or endocarditis)
15. Arterial tortuosity that would prevent the device from reaching the target vessel
16. Known hypersensitivity to nickel-titanium

    Imaging Exclusion Criteria:
17. Angiographic evidence of carotid dissection, complete cervical carotid occlusions, or vasculitis
18. Stenosis proximal to thrombus site that may preclude safe recovery of the device
19. Brain computed tomography (CT) with signs of hemorrhage, arteriovenous venous malformations, or aneurysm
20. Early ischemic changes greater than 1/3 of the middle cerebral artery (MCA) territory or according to brain computed tomography (CT) Alberta Stroke Program Early CT (ASPECT) score ≤ 6 or according to magnetic resonance diffusion weighted imaging (MR DWI) ASPECT score \<5
B: 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
C: Inclusion Criteria:

* Female or male inpatients
* Age: 18 - 80 years.
* Clinical diagnosis of ischemic stroke causing a measurable neurological deficit defined as impairment of language, motor function, cognition and/or gaze, vision or neglect. Ischemic stroke is defined as an event characterized by the sudden onset of an acute focal neurologic deficit presumed to be due to cerebral ischemia after CT scan excludes hemorrhage.
* Onset of symptoms between 3 and 4 hours prior to initiation of administration of study drug.
* Stroke symptoms are to be present for at least 30 minutes and have not significantly improved before treatment. Symptoms must be distinguishable from an episode of generalized ischemia (i.e. syncope), seizure, or migraine disorder.
* Patient is willing to participate voluntarily and to sign a written patient informed consent. Informed consent will be obtained from each patient or the subject's legally authorized representative or relatives, or deferred where applicable, according to the regulatory and legal requirements of the participating country.
* Patients who are unable to sign but who are able to understand the meaning of participation in the study may give an oral witnessed informed consent. These patients have to make clear undoubtfully that they are willing to participate voluntarily and must be able to understand an explanation of the contents of he information sheet.
* Willingness and ability to comply with the protocol.

Exclusion Criteria:

* Evidence of intracranial hemorrhage (ICH) on the CT-scan.
* Symptoms of ischaemic attack began more than 4 hours and 30 minutes prior to infusion start or when time of symptom onset is unknown.
* Minor neurological deficit or symptoms rapidly improving before start of infusion.
* Severe stroke as assessed clinically (e.g. NIHSS\>25) and/or by appropriate imaging techniques.
* Epileptic seizure at onset of stroke
* Symptoms suggestive of subarachnoid haemorrhage, even if the CT-scan is normal.
* Administration of heparin within the previous 48 hours and a thromboplastin time exceeding the upper limit of normal for laboratory
* History of prior stroke and concomitant diabetes. \* Prior stroke within the last 3 months
* Platelet below 100,000/mm3. \* Systolic blood pressure \>185 mmHg or diastolic blood pressure \>110 mmHg, or aggressive management (IV medication) necessary to reduce BP to these limits.
* Blood glucose \<50 or \> 400 mg/dl (\< 2.77 or \> 22.15 mmol / l). \* Known haemorraghic diathesis
* Patients receiving oral anticoagulants. \* Manifest or recent severe or dangerous bleeding
* Known history of or suspected intracranial haemorrhage
* Suspected subarachnoid haemorrhage or condition after subarachnoid haemorrhage from aneurysm
* History of central nervous system damage (i.e. neoplasm, aneurysm, intracranial or spinal surgery)
* Haemorrhagic retinopathy,e.g. in diabetes (vision disturbances may indicate haemorrhagic retinopathy)
* Recent (less than 10 days) traumatic external heart massage, obstetrical delivery, recent puncture of a non-compressible blood-vessel (e.g. subclavian or jugular vein puncture.
* bacterial endocarditis, pericarditis.\* Acute pancreatitis
* Documented ulcerative gastrointestinal disease during the last 3 months, oesophageal varices, arterial- aneurysm, arterial/venous malformation
* Neoplasm with increased bleeding risk
D: Inclusion Criteria:

* New focal disabling neurologic deficit consistent with acute cerebral ischemia (NIHSS \>/= 6)
* Age \>/= 18 ≤ 85
* Clot retrieval procedure can be initiated within 8 hours from onset
* Large vessel proximal anterior circulation occlusion on MR or CT angiography (internal carotid, M1 or M2 MCA)
* Pretreatment MRI performed according to MR RESCUE protocol
* Signed informed consent obtained from the patient or patient's legally authorized representative
* Premorbid modified Rankin score of 0-2
* Allowed but not required: patients treated with IV tPA (tissue plasminogen activator) up to 4.5 hours from symptom onset with persistent target occlusion on post-treatment MR RESCUE MR or CT protocol performed at the completion of drug infusion (Note: Rapidly improving neurological signs prior to randomization is an exclusion)

Exclusion Criteria:

* NIHSS \>/= 30
* Contraindication to MRI (pacemaker etc)
* Acute intracranial hemorrhage
* Coma
* Rapidly improving neurological signs prior to randomization
* Pre-existing medical, neurological or psychiatric disease that would confound the neurological, functional, or imaging evaluations
* Pregnancy
* Known allergy to iodine previously refractory to pretreatment medications
* Current participation in another experimental treatment protocol
* Contrast-Enhanced Neck MRA (magnetic resonance angiography) or CTA (computed tomography angiography) suggests proximal ICA occlusion, proximal carotid stenosis \> 67%, or dissection
* INR \> 3.0 (international normalized ratio)
* PTT \> 3 x Normal (partial thromboplastin time)
* Imaging data cannot be processed by the MR RESCUE computer
* Renal Failure (serum creatinine \> 2.0 or Glomerular Filtration Rate \[GFR\] \< 30)

MRI Exclusion Criteria:

* Contraindication to MRI (pacemaker, etc)

CT Exclusion Criteria:

* Contraindication to iodinated contrast\*\*

  \*\*Examples of possible iodinated contrast contraindications include:
* Hyperthyroidism
* History of severe allergic reaction to iodinated contrast material
* History of sever kidney disease as an adult, including tumor or transplant surgery, or family history of kidney failure
* Paraproteinemia syndromes or multiple myeloma
* Collagen vascular disease
* Severe cardiac insufficiency
* Severely compromised liver function
* Current therapy with metformin, aminoglycosides

Answer: B