The main objective of this study is to prospectively evaluate the safety, probable benefit, and effectiveness of the PHAROS Vitesse Neurovascular Stent System in a multicenter, randomized clinical trial.

A secondary objective of this study is to evaluate the impact of stenting in the neurovasculature to treat cerebral ischemia on other outcomes such as hospital length of stay, charges, and costs.

1.1 Study Hypothesis Treatment of cerebral or retinal ischemia due to plaque in the neurovasculature using the PHAROS Vitesse Stent System plus medical therapy will provide additional clinical benefit over medical therapy alone.

1.2 Primary Effectiveness Endpoint

The primary effectiveness endpoint consists of a composite of the two following outcomes:

• Stroke in the same territory (distal to the target lesion) as the presenting event within 12 months of randomization
• Hard TIA in the same territory (distal to the target lesion) as the presenting event from day 2 through month 12 post-randomization

1.3 Safety Outcomes

Safety outcomes to be collected and reported as part of the overall risk-to-benefit profile for this device are:

• Stroke in any territory within 30 days of randomization
• Death from any cause within 30 days of randomization
• Hard TIA in any territory occurring after a 24 hour post-procedure stabilization period (days 2-30) since the recovery from anesthesia can mask accurate assessment of possible TIA symptoms.
• Intracranial hemorrhage within 30 days of randomization

1.4 Other Outcomes

• Stent Success - PHAROS Vitesse stent deployed across target lesion with residual stenosis 0-20%
• Percentage of Stent Group Subjects with any (symptomatic or asymptomatic) in-stent restenosis ≥ 70% confirmed by angiogram at 12 months
• Percentage of Stent Group Subjects with symptomatic in-stent restenosis ≥ 70% confirmed by angiogram at 12 months
• Percentage of Medical Therapy Group Subjects with interventional procedure (e.g., angioplasty or stent) at 12 months
• Comparison of NIHSS scores between treatment arms
• Comparison of mRS scores between treatment arms

Inclusion Criteria:

1. Subject has at least one neurovascular lesion (70-99%) stenosis [internal carotid, middle cerebral, vertebral artery (C4-BA), and/or basilar artery] symptomatic with a hard TIA or stroke attributable to the territory of the lesion within the past 30 days. An intracranial tandem lesion (50-99%) stenosis may be treated if normal artery segment is sufficient length to avoid overlapping stents.

2. Target vessel diameter / lesion length measurements are within one of the below per angiogram:

   • Vessel diameter is ≥ 2.0 mm and < 2.5 mm / lesion length is ≤ 16 mm, or
   • Vessel diameter is ≥ 2.5 mm and < 3.0 mm / lesion length is ≤ 18 mm, or
   • Vessel diameter is ≥ 3.0 mm and < 4.5 mm / lesion length is ≤ 26 mm, or
   • Vessel diameter is ≥ 4.5 mm and ≤ 5.0 mm / lesion length is ≤ 31 mm

3. Subject has normal artery adjacent to each stenosis; diameter 2.0 mm - 5.0 mm

4. Subject age is 18-85 years

5. Life expectancy is at least 2 years

6. Subject 's mRS score is ≤ 3

7. Subject is available for study follow-up visits (e.g., lives within 3 hours of research center)

8. Subject is willing and cognitively able to provide Informed Consent (consent may be indicated verbally and signed by neutral witness if stroke has impaired hand or visual function)

Exclusion Criteria:

1. Subject has contraindications for balloon expandable stent, e.g.

   • Extreme tortuosity at, or proximal to, target lesion,
   • More than 2 lesions with > 50% stenosis (including vertebral ostia and common carotid disease),
   • Carotid or vertebral dissection

2. CT scan or MRI evidence of any of the following:

   • Intracranial hemorrhage of type PH1 or PH2
   • Subdural or epidural hemorrhage
   • Mass effect, or
   • Intracranial tumor (except small meningioma)

3. Subject has a previous stent in the territory of the target lesion(s)

4. Subject has a previous coil or clip placed in the territory of the target lesion within 6 months

5. Subject has a potential source of cardiac embolism requiring anticoagulation therapy (e.g., atrial fibrillation, intracardiac thrombus or vegetation, significant mitral stenosis, mechanical heart valve, congestive heart failure with EF <30%, or endocarditis)

6. Subject has concurrent intracranial pathology, e.g.

   • Moyamoya
   • Vasculitis documented by biopsy results
   • Ruptured Aneurysm
   • Unruptured aneurysm > 7mm

7. Subject has uncontrolled hypertension (systolic >185 mmHg or diastolic >110 mmHg)

8. Hemoglobin < 10 g/dL; platelet count < 100,000; or INR > 1.5 (e.g., use of warfarin)

9. Subject has an uncorrectable bleeding diathesis

10. Subject's neurological status is unstable and rapidly declining (NIHSS score increased > 4 points within 48 hours prior to randomization)

11. Subject has a contraindication for combination antithrombotic treatment (e.g., clopidogrel and aspirin) such as peptic ulcer disease

12. Subject history indicates high risk of non-compliance (e.g., substance abuse, psychosocial issues, etc.)

13. Subject has a known history contraindicating contrast dye or iodine (vs. sensitivity which can be safely controlled by antihistamine, steroid, etc.)

14. Subject is pregnant or plans to become pregnant in the next 12 months

15. Myocardial infarction within past 3 months

16. Treatment with tPA or other thrombolytic agent within 48 hours prior to randomization

17. Major surgery or trauma within 2 weeks prior to randomization

18. Enrollment in another investigational device or drug study that may confound the results

Analyses were based on an Intent-to-Treat (ITT) population, defined ad enrolled subjects who met the inclusion/exclusion criteria and who were randomized post angiogram. Stent and medical Therapy Group subjects were analyzed to their ITT randomized group regardless of treatment received.

Adverse events were collect from time of baseline angiogram/stent procedure through subject end of study (either early termination or 12 month post procedure follow up visit)

Adverse events collected and were summarized according to how they were reported by investigational sites

Early termination of enrollment led to small numbers of subjects analyzed (less than 50% of the prospectively planned sample size). Various endpoints, subgroup and sensitivity analyses were not conducted because the study was not fully enrolled.