Safety and Efficacy Study for Reverse Flow Used During Carotid Artery Stenting Procedure

Cerebral embolization during carotid artery stenting (CAS) can often precipitate severe
adverse neurological effects. Most major clinical studies of CAS have used distal filters
for cerebral protection and have compared the neurologic complication rates with those of
carotid endarterectomy (CEA). Many currently available embolic protection devices, however,
have limited efficacy in capturing microembolic debris that is liberated during stenting,
pre-dilatation and post-dilatation. Distal protection systems are furthermore limited by the
need to cross the lesion prior to deployment. Some studies have shown a relatively high
incidence of cerebral infarction even when distal protection devices are employed.

Cerebral protection with carotid flow reversal is a method that was developed as an
alternative to the use of distal protection devices. While novel in its approach, this
method too has its limitations. Another technique developed employs carotid flow reversal
prior to traversing the stenosis and can be accomplished by directly accessing the carotid
anatomy without the use of the transfemoral approach. Major benefits to this method include
a simpler route to the target lesion and the ability to perform the procedure on patients
with severe carotid tortuosity and difficult aortic arch anatomy.

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 >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 (or their legal guardian) 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 surgical high-risk criteria.

Exclusion Criteria:

1. Chronic atrial fibrillation, any episode of paroxysmal atrial fibrillation within the
past 6 months, or history of paroxysmal atrial fibrillation requiring chronic
anticoagulation.

2. Evolving stroke, severe dementia, intracranial tumor, history of spontaneous
intracranial hemorrhage within the past 12 months, recent stroke of sufficient size,
hemorrhagic transformation of an ischemic stroke within the past 60 days, history of
major stroke with major neurological deficit.

3. Active bleeding diathesis or coagulopathy or will refuse blood transfusion.

4. Had or will have CABG, endovascular stent procedure, valve intervention or vascular
surgery within 30 days before or after the intervention.

5. Recently (<60 days prior to procedure) implanted heart valve (either surgically or
endovascularly), which is a known source of emboli as confirmed on echocardiogram.

6. Recent GI bleed that would interfere with antiplatelet therapy.

7. Life expectance of < 12 months post procedure.

8. History of intolerance or allergic reaction to any of the study medications or stent
materials.

9. Myocardial Infarction within 72 hours prior to the intervention.

10. Has had neurologic illnesses within the past two years characterized by fleeting or
fixed neurologic deficit which cannot be distinguished from TIA or stroke.

11. 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.

12. Occlusion or (TIMI 0) "string sign" >1cm of the ipsilateral common or internal
carotid artery.

13. Has vertebrobasilar insufficiency symptoms only, without clearly identifiable
symptoms referable to the study carotid artery.

14. Knowledge of cardiac sources of emboli, Ostium of Common Carotid Artery (CCA)
requires revascularization.

15. Presence of extensive or diffuse atherosclerotic disease involving the proximal
common carotid artery that would preclude the safe introduction of the study device.

16. Has less than 5cm between the clavicle and bifurcation.

17. Bilateral carotid stenosis if intervention is planned within the 30-day of the index
procedure.

18. An intraluminal filling defect that is not associated with an ulcerated target
lesion.

19. Abnormal angiographic findings.

20. Previous intervention in the ipsilateral proximal CCA or previous placed
intravascular stent in target vessel