Please select the eligibility criteria that correspond to the clinical trial below.
Title: Effects of Carotid Stent Design on Cerebral Embolization
Brief Summary: The goal of the proposed study is to contrast the relative efficacy of closed-cell stents versus open-cell stents in preventing periprocedural cerebral embolization in high-risk patients with symptomatic and asymptomatic extracranial carotid stenosis undergoing carotid artery stenting (CAS).


Options:
A: Inclusion Criteria:

1. The patient must be \> 18 years of age.
2. The patient has a 50% stenosis (as determined by ultrasound or angiogram) of the common or internal carotid artery and is clinically symptomatic; i.e., within the previous 180 days has experienced symptoms in the ipsilateral carotid artery distribution, defined as:

   * one or more TIAs, characterized by distinct focal neurologic dysfunction or monocular blindness with clearing of signs and symptoms within 24 hours, or
   * one or more completed strokes (as defined by this protocol) with persistence of symptoms or signs for more than 24 hours (the most recent event is used as the qualifying event), except as excluded below, with stenosis \>50%, (as determined by ultrasound or angiogram) of the common or internal carotid artery, OR The patient must have a \>80% diameter stenosis (as determined by ultrasound or angiogram) of the internal or common carotid artery without neurological symptoms.
3. To be entered into the study, the patient must have one or more of the following conditions:

   * congestive heart failure (class III/IV) and/or known severe left ventricular dysfunction LVEF \< 30%
   * open heart surgery within six weeks
   * recent MI (\>24 hours and \<4 weeks)
   * unstable angina (CCS class III/IV)
   * synchronous severe cardiac and carotid disease requiring open heart surgery and carotid revascularization
   * Age greater than 80 years as a single risk factor.

Exclusion Criteria:

1. The patient is experiencing an acute ischemic neurologic stroke or has experienced a stroke within the past 48 hours.
2. The patient has an intracranial mass lesion (i.e., abscess, tumor, or infection).
3. The reference segment diameter (distal common carotid and internal carotid artery segment cephalic to the lesion) is less than 4mm or greater than 9mm by quantitative analysis. See Instructions For Use, for proper stent sizing. The exception to this would be with a lesion having \>95% stenosis where the true diameter of the distal vessel can not be determined such as the case with a string sign or distal vessel collapse. In this case the judgment of the interventionalist will prevail with the intention not to oversize the stent to the distal vessel by more than 2mm.
4. The patient has known peripheral vascular, supra-aortic or internal carotid artery tortuosity which preclude the use of catheter-based techniques if so randomized.
5. The patient has any intracranial aneurysm (\> 9 mm).
B: Inclusion Criteria:

* In brief, patients are eligible if they have experienced a carotid TIA or non disabling stroke within 4 months before randomisation and if they have an atherosclerotic stenosis of the region of the ipsilateral carotid bifurcation of 60% or more, as determined by the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method, that investigators believe is suitable for both carotid endarterectomy and endovascular treatment. The degree of stenosis warranting treatment initially set at 70% or more was subsequently set at 60% or greater to reflect current generally accepted practice in the treatment of symptomatic carotid stenosis. The presence of a 60% or more ipsilateral carotid stenosis has to be confirmed by conventional digital subtraction angiography or the combination of carotid Duplex scanning and magnetic resonance angiography, provided the results of these non-invasive techniques are concordant.

Exclusion Criteria:

* Patients cannot be included if they have a disabling stroke (mRS \>=3), a non atherosclerotic carotid disease, a severe intracranial carotid artery stenosis, contra-indications to heparin, ticlopidine or clopidogrel.
* There is no age limit.
* The presence of contralateral occlusion and/or the angiographic appearance of the stenotic lesion are not factors in treatment selection. The randomisation algorithm takes centre and degree of stenosis (more or less than 90% stenosis) into account. Patients must be treated as soon as possible after random assignment, in any case within 2 weeks of randomisation.
C: Inclusion Criteria:

* Subject is at high risk for carotid endarterectomy due to either anatomic or co-morbid conditions; AND
* Symptomatic patients (TIA or non-disabling stroke within 6 months of the procedure), with carotid stenosis ≥ 50% as diagnosed by angiography, using NASCET methodology (50); OR
* Asymptomatic patients with carotid stenosis ≥ 80% as diagnosed by angiography, using NASCET methodology

Exclusion Criteria:

* Conditions that interfere with the evaluation of endpoints
* Subject has anticipated or potential sources of cardiac emboli
* Subject plans to have a major surgical procedure within 30 days after the index procedure.
* Subject has intracranial pathology that makes the subject inappropriate for study participation.
* Subject has a total occlusion of the ipsilateral carotid artery (i.e., CCA).
* Severe circumferential lesion calcification that may restrict the full deployment of the carotid stent.
* Carotid stenosis located distal to the target stenosis that is more severe than the target stenosis.
D: Inclusion Criteria:

1. Patient must meet one of the following criteria regarding neurological symptom status and degree of stenosis:

   * Symptomatic: Stenosis must be greater than or equal to 50% as determined by angiogram and the patient has a history of stroke (minor or non-disabling), TIA and/or amaurosis fugax within 180 days of the procedure.
   * Asymptomatic: Stenosis must be greater than or equal to 70% as determined by angiogram without any neurological symptoms within the prior 180 days.
2. Target vessel must meet diameter requirements for stent (refer to selected stent IFU for diameter requirements).
3. Patient has a discrete lesion located in the internal carotid artery (ICA) with or without involvement of the contiguous common carotid artery (CCA).
4. Patient is greater or equal to 18 years of age.
5. Patient has no childbearing potential or has a negative pregnancy test within one week prior to the study procedure.
6. Patient understands the nature of the procedure and has provided a signed informed consent using a form that has been reviewed and approved by the Investigational Review Board/Ethics Committee of the respective clinical site prior to the procedure. This will be obtained prior to participation in the study.
7. Patient is willing to comply with the protocol requirements and return to the treatment center for all required clinical evaluations.
8. Patient meets at least one of the anatomic or clinical high-risk criteria.

Exclusion Criteria:

1. Patient has chronic atrial fibrillation.
2. Patient has had any episode of paroxysmal atrial fibrillation within the past 6 months, or history of paroxysmal atrial fibrillation requiring chronic anticoagulation.
3. Patient has an evolving stroke.
4. Patient has severe dementia.
5. Patient has a history of spontaneous intracranial hemorrhage within the past 12 months.
6. Patient has had a recent (\<7 days) stroke of sufficient size (on CT or MRI) to place him or her at risk of hemorrhagic conversion during the procedure.
7. Patient had hemorrhagic transformation of an ischemic stroke within the past 60 days.
8. Patient has active bleeding diathesis or coagulopathy or will refuse blood transfusion.
9. Patient had or will have CABG, endovascular stent procedure, valve intervention or vascular surgery within 30 days before or after the intervention.
10. Patient has had a recent GI bleed that would interfere with antiplatelet therapy.
11. Life expectancy of \< 12 months post procedure.
12. Patient has history of intolerance or allergic reaction to any of the study medications or stent materials (refer to stent IFU), including aspirin (ASA), ticlopidine, clopidogrel, prasugrel, statin or contrast media (that can't be pre medicated). Patients must be able to tolerate statins and a combination of ASA and ticlopidine, ASA and clopidogrel or ASA and prasugrel.
13. Myocardial Infarction within 72 hours prior to the intervention.
14. Presence of a previous placed intravascular stent in target vessel or the planned arteriotomy site.
15. Patient has had neurologic illnesses within the past two years characterized by fleeting or fixed neurologic deficit which cannot be distinguished from TIA or stroke (e.g. partial or secondarily generalized seizures, complicated or classic migraine, tumor or other space-occupying brain lesions, subdural hematoma, cerebral contusion or other post-traumatic lesions, intracranial infection, demyelinating disease, moderate to severe dementia, or intracranial hemorrhage).
16. Patient with a history of major stroke (CVA or retinal embolus) with major neurological deficit likely to confound study endpoints within 1 month of index procedure.
17. Patient has Hgb \<10 g/dl, platelet count \<125,000/μl, uncorrected INR \>1.5, bleeding time \>1 minute beyond upper limit normal, or heparin-associated thrombocytopenia.
18. Patient has an intracranial tumor.
19. Patient is actively participating in another drug or device trial (IND or IDE) that has not completed the required protocol follow-up period.
20. Patient has inability to understand and cooperate with study procedures or provide informed consent.
21. Occlusion or \[Thrombolysis In Myocardial Infarction Trial (TIMI 0)\] "string sign" \>1cm of the ipsilateral common or internal carotid artery.
22. Patient has vertebrobasilar insufficiency symptoms only, without clearly identifiable symptoms referable to the study carotid artery.
23. Knowledge of cardiac sources of emboli.e.g. left ventricular aneurysm, intracardiac filling defect, cardiomyopathy, aortic or mitral prosthetic heart valve, calcific aortic stenosis, endocarditis, mitral stenosis, atrial septal defect, atrial septal aneurysm, or left atrial myxoma).
24. Recently (\<60 days) implanted heart valve (either surgically or endovascularly), which is a known source of emboli as confirmed on echocardiogram.
25. Ostium of Common Carotid Artery (CCA) requires revascularization.
26. Presence of extensive or diffuse atherosclerotic disease involving the proximal common carotid artery that would preclude the safe introduction of the study device.
27. The patient has less than 5cm between the clavicle and bifurcation, as assessed by duplex Doppler ultrasound.
28. Bilateral carotid stenosis if intervention is planned within 37 days of the index procedure.
29. An intraluminal filling defect (defined as an endoluminal lucency surrounded by contrast, seen in multiple angiographic projections, in the absence of angiographic evidence of calcification) that is not associated with an ulcerated target lesion.
30. Abnormal angiographic findings: ipsilateral intracranial or extracranial arterial stenosis greater in severity than the lesion to be treated, cerebral aneurysm \> 5 mm, AVM (arteriovenous malformation) of the cerebral vasculature, or other abnormal angiographic findings.
31. Patient has had a previous intervention in the ipsilateral proximal CCA.
32. Patient has had a TIA or amaurosis fugax within 48 hours prior to the procedure.
33. Patient has contralateral lateral recurrent, laryngeal or vagus nerve injury.
34. Patient is otherwise unsuitable for intervention in the opinion of the investigator.

Answer: C