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

This study has been completed.
Information provided by (Responsible Party):
Silk Road Medical Identifier:
First received: September 10, 2012
Last updated: December 16, 2016
Last verified: December 2016
The purpose of this study is to evaluate the safety and effectiveness of the MICHI™ Neuroprotection System with Filter (MICHI™ NPS+f) in providing cerebral embolic protection during carotid artery stenting. It will be used in conjunction with a FDA approved carotid artery stent for the treatment of carotid artery disease.

Condition Intervention Phase
Carotid Artery Disease
Device: MICHI NPS+f
Phase 3

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Prevention

Resource links provided by NLM:

Further study details as provided by Silk Road Medical:

Primary Outcome Measures:
  • Stroke, Myocardial Infarction, and Death [ Time Frame: 30 days post procedure ]
    The primary endpoint for overall evaluation of the study is a composite endpoint consisting of the first occurrence of any of the following major adverse events within 30 days.

Secondary Outcome Measures:
  • Technical Success [ Time Frame: 0 to 30 days ]
    The analyses to be conducted on the secondary endpoints are intended to provide additional supportive evidence of the efficacy and safety of the device.

  • Acute Device Success [ Time Frame: 0 to 30 days ]
    The analyses to be conducted on the secondary endpoints are intended to provide additional supportive evidence of the efficacy and safety of the device.

  • Procedural Success [ Time Frame: 0 to 30 days ]
    The analyses to be conducted on the secondary endpoints are intended to provide additional supportive evidence of the efficacy and safety of the device.

  • Access Site Complications [ Time Frame: 0 to 30 days ]
    The analyses to be conducted on the secondary endpoints are intended to provide additional supportive evidence of the efficacy and safety of the device.

  • Contrast Usage [ Time Frame: 0 to 30 days ]
    The analyses to be conducted on the secondary endpoints are intended to provide additional supportive evidence of the efficacy and safety of the device.

  • Ipsilateral Stroke [ Time Frame: 31-365 days ]
    Data on ipsilateral stroke 31-365 days post procedure will be collected to provide additional supportive evidence of the safety of the device.

Enrollment: 286
Study Start Date: November 2012
Study Completion Date: July 2016
Primary Completion Date: March 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: MICHI NPS+f
The MICHI™ NPS+f is a flow reversal circuit consisting of two proprietary sheaths connected by standard surgical tubing. The sheaths each have a standard hemostasis valve and sidearm. An in-line flow regulator allows the clinician to modify to the flow through the circuit (either high flow or low flow) in addition to permitting temporary cessation of flow.
Device: MICHI NPS+f
Cerebral protection with carotid flow reversal
Other Name: ENROUTE Transcarotid Neuroprotection System

Detailed Description:

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.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01685567

United States, California
Peter Morton UCLA Medical Center
Los Angeles, California, United States, 90095
United States, Florida
Florida Hospital
Orlando, Florida, United States, 32804
United States, Maryland
Johns Hopkins Bayview Medical Center
Baltimore, Maryland, United States, 21224
United States, Massachusetts
Massachusetts General Hospital
Boston, Massachusetts, United States, 02114
United States, Michigan
University of Michigan Medical Center
Ann Arbor, Michigan, United States, 48109-5967
McLaren Regional Medical Center
Flint, Michigan, United States, 48507
United States, Missouri
Washington University School of Medicine
St. Louis, Missouri, United States, 63110
United States, New York
Albany Medical Center
Albany, New York, United States, 12208
University at Buffalo Neurosurgery, Inc
Buffalo, New York, United States, 14203
Columbia University
New York, New York, United States, 10032
United States, Ohio
Cleveland Clinic Foundation
Cleveland, Ohio, United States, 44106
University Hospitals Case Medical Center and Case Western Reserve University School of Medicine
Cleveland, Ohio, United States, 44106
Riverside Methodist Hospital
Columbus, Ohio, United States, 43214
Jobst Vascular Institute
Toledo, Ohio, United States, 43606
United States, Oklahoma
Oklahoma Heart
Oklahoma City, Oklahoma, United States, 73120
United States, South Carolina
Greenville Hospital System
Greenville, South Carolina, United States, 29615
United States, Texas
Cardiothoracic & Vascular Surgeons
Austin, Texas, United States, 78756
Methodist Medical Center
Dallas, Texas, United States, 75208
Dallas VA Medical Center
Dallas, Texas, United States, 75216
United States, Virginia
Sentara Vascular Specialists
Norfolk, Virginia, United States, 23507
Hospital Virgen de la Salud
Toledo, Spain, 45004
Sponsors and Collaborators
Silk Road Medical
Principal Investigator: Christopher Kwolek, MD Massachusetts General Hospital
Principal Investigator: Richard Cambria, MD Massachusetts General Hospital
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Silk Road Medical Identifier: NCT01685567     History of Changes
Other Study ID Numbers: SRM-2012-02 
Study First Received: September 10, 2012
Last Updated: December 16, 2016

Keywords provided by Silk Road Medical:
carotid artery disease
reverse flow

Additional relevant MeSH terms:
Carotid Artery Diseases
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Vascular Diseases
Cardiovascular Diseases processed this record on February 20, 2017