Please select the eligibility criteria that correspond to the clinical trial below.
Title: Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy
Brief Summary: The purpose of this study is to compare the effectiveness of treating acute ischemic stroke with mechanical embolectomy using the Merci Retriever or the Penumbra System within 8 hours of symptom onset to standard medical treatment, and to identify people who might benefit from mechanical embolectomy by the appearance of stroke on multimodal computerized tomography (CT) or magnetic resonance (MR) imaging.


Options:
A: Inclusion Criteria:

1. Age 18 and older (i.e., candidates must have had their 18th birthday)
2. NIHSS ≥8 at the time of neuroimaging
3. Presenting or persistent symptoms within 6 hours of when groin puncture can be obtained
4. Neuroimaging demonstrates large vessel proximal occlusion (distal ICA through MCA bifurcation)
5. The operator feels that the stroke can be appropriately treated with traditional endovascular approaches (the ADAPT approach or conventional first-line stent retriever approach)
6. Pre-event Modified Rankin Scale score 0-1
7. Non-contrast CT/CTA for trial eligibility performed or repeated at treating ADAPT stroke center.
8. Consenting requirements met according to local IRB

Exclusion Criteria:

1. Patient is more than 6-hours from symptom onset
2. Rapidly improving neurologic examination
3. Absence of large vessel occlusion on non-invasive imaging
4. Presence of an existing or pre-existing large territory infarction
5. Known or suspected pre-existing (chronic) large vessel occlusion in the symptomatic territory
6. Absent femoral pulses
7. Excessive vascular access tortuosity that will likely result in unstable access platform.
8. Pregnancy; if a woman is of child-bearing potential a urine or serum beta HCG test is positive.
9. Severe contrast allergy or absolute contraindication to iodinated contrast.
10. Clinical history, past imaging or clinical judgment suggests that the intracranial occlusion is chronic.
11. Patient has a severe or fatal comorbidities that will likely prevent improvement or follow-up or that will render the procedure unlikely to benefit the patient.

Head CT or MRI Scan Exclusion Criteria

* Presence of blood on imaging (subarachnoid hemorrhage (SAH)), intracerebral hemorrhage (ICH), etc.)
* High density lesion consistent with hemorrhage of any degree
* Significant mass effect with midline shift
* Core infarct lesion volume \>50 cc.
* 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.
B: Inclusion Criteria:

1. Age 18 - 80
2. Clinical signs consistent with acute ischemic stroke
3. Prestroke Modified Rankin Score ≤ 1
4. NIHSS ≥ 8 and \< 30 at the time of randomization
5. Initiation of IV t-PA within 4.5 hours of onset of stroke symptoms (onset time is defined as the last time when the patient was witnessed to be at baseline), with investigator verification that the subject has received / is receiving the correct IV t-PA dose for the estimated weight prior to randomization.
6. Thrombolysis in Cerebral Infarction (TICI) 0-1 flow in the intracranial internal carotid artery, M1 segment of the MCA, or carotid terminus confirmed by CT or MR angiography that is accessible to the Solitaire™ FR Device.
7. Subject is able to be treated within 6 hours of onset of stroke symptoms and within 1.5 hours (90 minutes) from CTA or MRA to groin puncture.
8. Subject is willing to conduct protocol-required follow-up visits.
9. An appropriate signed and dated Informed Consent Form (as allowed according to country regulations and approved by ethics committee and/or IRB) has been obtained
10. Subject is affiliated with a social security system (if required by individual country regulations).
11. Subject meets national regulatory criteria for clinical trial participation.

Exclusion Criteria:

1. Subject who is contraindicated to IV t-PA as per local national guidelines.
2. Female who is pregnant or lactating or has a positive pregnancy test at time of admission.
3. As applicable by French law, subject who is a protected individual such as an incompetent adult or incarcerated person.
4. Rapid neurological improvement prior to study randomization suggesting resolution of signs/symptoms of stroke.
5. Known serious sensitivity to radiographic contrast agents.
6. Known sensitivity to Nickel, Titanium metals or their alloys.
7. Current participation in another investigational drug or device treatment study.
8. 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 enrollment.)
9. Renal Failure as defined by a serum creatinine \> 2.0 mg/dl (or 176.8 μmol/l) or Glomerular Filtration Rate \[GFR\] \< 30Warfarin therapy with INR greater than 1.7.
10. Subject who requires hemodialysis or peritoneal dialysis, or who have a contraindication to an angiogram for whatever reason
11. Life expectancy of less than 90 days.
12. Clinical presentation suggests a subarachnoid hemorrhage, even if initial CT or MRI scan is normal.
13. Suspicion of aortic dissection.
14. Subject with a co-morbid disease or condition that would confound the neurological and functional evaluations or compromise survival or ability to complete follow-up assessments.
15. Subject currently uses or has a recent history of illicit drug(s) or abuses alcohol (defined as regular or daily consumption of more than 4 alcoholic drinks per day).
16. Known history of arterial tortuosity, pre-existing stent, and/or other arterial disease which would prevent the device from reaching the target vessel and/or preclude safe recovery of the device.

Imaging Exclusion Criteria:

1. Computed tomography (CT) or Magnetic Resonance Imaging (MRI) evidence of hemorrhage on presentation.
2. CT or MRI evidence of mass effect or intra-cranial tumor (except small meningioma).
3. CT or MRI evidence of cerebral vasculitis.
4. CT showing hypodensity or MRI showing hyperintensity involving greater than 1/3 of the middle cerebral artery (MCA) territory (or in other territories, \>100 cc of tissue) on presentation.
5. Baseline non-contrast CT or DWI MRI evidence of a moderate/large core defined as extensive early ischemic changes of Alberta Stroke Program Early CT score (ASPECTS) \< 6.
6. CT or MRI evidence of a basilar artery (BA) occlusion or posterior cerebral artery (PCA) occlusion.
7. CTA or MRA evidence of carotid dissection or complete cervical carotid occlusion requiring stenting at the time of the index procedure (i.e., mechanical thrombectomy)
8. 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).
C: 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
D: Inclusion Criteria:

1. age (18-80 years)
2. acute ischemic stroke
3. within 8 hours after symptom onset
4. a large-vessel confirmed by CTA/MRA (eg, internal carotid, middle cerebral M1 and/or M2 segments)
5. NIHSS(≥8 and ≤24)
6. patients or their legally authorised representatives provided signed, informed consent.

Exclusion Criteria:

1. CT or MRI evidence of intracranial haemorrhage/tumor
2. major ischaemic infarction (acute ischaemic change in more than a third of the middle cerebral artery territory)
3. NIHSS(≥25 and ≤7)
4. severe sustained hypertension (systolic blood pressure \>185 mm Hg or diastolic blood pressure \>110 mm Hg)
5. baseline glucose concentrations of less than 2·7 mmol/L or higher than 21.6 mmol/L
6. known haemorrhagic diathesis, coagulation factor deficiency, or oral anticoagulant therapy with an international normalised ratio of more than 1.7
7. treatment with heparin within 48 h with a partial thromboplastin time more than two times the laboratory normal, baseline platelet count of less than 100×10\^9/L
8. history of severe allergy (worse than rash) to contrast medium or nitinol
9. pregnancy

Answer: C