Post-approval Study of Transcarotid Artery Revascularization in Standard Risk Patients With Significant Carotid Artery Disease

Post-approval Study of Transcarotid Artery Revascularization in Standard Risk Patients With Significant Carotid Artery Disease. The ROADSTER 3 Study

The study objective is to evaluate real world usage of the ENROUTE Transcarotid Stent when used with the ENROUTE Transcarotid Neuroprotection System in patients at standard risk for adverse events from carotid endarterectomy

Study Overview

• Status: Completed
• Conditions: Carotid Artery Diseases
• Intervention / Treatment: Procedure: Transcarotid Artery Revascularization (TCAR)

Detailed Description

This is an open label, single arm, multi-center post-approval study for the treatment of patients at standard risk for adverse events from carotid endarterectomy who require carotid revascularization and who are eligible for treatment using the ENROUTE Transcarotid Stent System and the ENROUTE Transcarotid Neuroprotection System. The study will enroll a maximum of 400 patients treated per protocol at 30-60 sites in the United States.

• Study Type: Observational
• Enrollment (Actual): 344

Contacts and Locations

Study Locations

• United States
  • Alabama
    • Huntsville, Alabama, United States, 35801
      • Valley Vascular Consultants
  • Arizona
    • Scottsdale, Arizona, United States, 85258
      • HonorHealth
    • Tucson, Arizona, United States, 85718
      • Pima Heart & Vascular
  • California
    • La Jolla, California, United States, 92037
      • University of California, San Diego (UCSD)
    • La Mesa, California, United States, 91942
      • Sharp Grossmont
    • Los Angeles, California, United States, 90024
      • University of California, Los Angeles (UCLA)
  • Connecticut
    • New Haven, Connecticut, United States, 06519
      • Yale University
  • District of Columbia
    • Washington, District of Columbia, United States, 20010
      • Medstar Washington Hospital Center
  • Florida
    • Clearwater, Florida, United States, 33756
      • Morton Plant Hospital
    • Delray Beach, Florida, United States, 33484
      • Delray Medical Center
    • Miami Beach, Florida, United States, 33140
      • Mount Sinai Medical Center
    • Ocala, Florida, United States, 34471
      • AdventHealth Ocala
    • Pensacola, Florida, United States, 32504
      • Coastal Vascular & Interventional
  • Georgia
    • Cumming, Georgia, United States, 30342
      • Northside Vascular
  • Illinois
    • Elk Grove Village, Illinois, United States, 60007
      • Alexian Brothers Medical Center
    • Urbana, Illinois, United States, 61801
      • Carle Health
  • Indiana
    • Evansville, Indiana, United States, 47710
      • Deaconess Research / Evansville Surgical Associates
    • Indianapolis, Indiana, United States, 46202
      • Indiana University
  • Louisiana
    • Baton Rouge, Louisiana, United States, 70809
      • Baton Rouge General
    • Lafayette, Louisiana, United States, 70508
      • Acadiana Vascular Clinic / Our Lady Lourdes Heart Hospital
  • Maine
    • Portland, Maine, United States, 04102
      • Maine Medical Center
  • Massachusetts
    • Boston, Massachusetts, United States, 02215
      • Beth Israel Deaconess Medical Center
  • Michigan
    • Bay City, Michigan, United States, 48708
      • McLaren Heart & Vascular
    • Grand Rapids, Michigan, United States, 49503
      • Corewell Health
  • Minnesota
    • Minneapolis, Minnesota, United States, 55407
      • Abbott Northwestern
  • Missouri
    • Chesterfield, Missouri, United States, 63017
      • St. Luke's Hospital
    • North Kansas City, Missouri, United States, 64116
      • Midwest Aortic & Vascular Institute
  • New Hampshire
    • Lebanon, New Hampshire, United States, 03756
      • Dartmouth-Hitchcock Medical Center
  • New Jersey
    • Hackensack, New Jersey, United States, 07601
      • Hackensack University Medical Center
  • New York
    • New Hyde Park, New York, United States, 11040
      • Long Island Jewish Medical Center
    • New York, New York, United States, 10016
      • New York University
    • New York City, New York, United States, 10029
      • The Mount Sinai Hospital
    • Rochester, New York, United States, 14623
      • University of Rochester
  • North Carolina
    • Charlotte, North Carolina, United States, 28203
      • Atrium Health
    • Raleigh, North Carolina, United States, 27710
      • Duke University
  • Ohio
    • Cincinnati, Ohio, United States, 45242
      • Bethesda North Hospital
  • Oregon
    • Bend, Oregon, United States, 97701
      • St. Charles Health System
    • Portland, Oregon, United States, 97225
      • Providence St. Vincent
  • Pennsylvania
    • Bethlehem, Pennsylvania, United States, 18015
      • St. Luke's University Hospital
    • Harrisburg, Pennsylvania, United States, 17050
      • UPMC Pinnacle
    • Lancaster, Pennsylvania, United States, 17602
      • Lancaster General Hospital
    • Pittsburgh, Pennsylvania, United States, 15212
      • Allegheny General Hospital
  • South Carolina
    • Charleston, South Carolina, United States, 29401
      • Medical University of South Carolina (MUSC)
  • Tennessee
    • Germantown, Tennessee, United States, 38138
      • Stern Cardiovascular
    • Memphis, Tennessee, United States, 38120
      • Cardiovascular Surgery Clinic
  • Texas
    • Austin, Texas, United States, 78756
      • Cardiothoracic and Vascular Surgeons
    • Dallas, Texas, United States, 75146
      • Baylor Scott & White Dallas
    • Houston, Texas, United States, 77030
      • Memorial Hermann Southeast
    • Plano, Texas, United States, 75093
      • Baylor Scott & White Plano
    • Sugarland, Texas, United States, 77479
      • Houston Methodist Sugarland
  • Virginia
    • Norfolk, Virginia, United States, 23507
      • Sentara
    • Roanoke, Virginia, United States, 24014
      • Carilion Roanoke Memorial
  • West Virginia
    • Charleston, West Virginia, United States, 25304
      • Charleston Area Medical Center (CAMC)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 79 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patient with discrete lesion located in the internal carotid artery (ICA) with or without involvement of the contiguous common carotid artery (CCA) determined by duplex ultrasound, CT/CTA, MR/MRA or angiography.

-Symptomatic: ≥70% stenosis of the common or internal carotid artery by ultrasound or ≥50% stenosis of the common or internal carotid artery by angiogram

Or

-Asymptomatic: ≥70% stenosis of the common or internal carotid artery by ultrasound or ≥60% stenosis of the common or internal carotid artery by angiogram

Description

Inclusion Criteria:

1. Patient has a discrete lesion located in the internal carotid artery (ICA) with or without involvement of the contiguous common carotid artery (CCA) determined by duplex ultrasound, CT/CTA, MR/MRA or angiography.

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

   Symptomatic: ≥70% stenosis of the common or internal carotid artery by ultrasound or ≥50% stenosis of the common or internal carotid artery by angiogram

   OR

   Asymptomatic: ≥70% stenosis of the common or internal carotid artery by ultrasound or ≥60% stenosis of the common or internal carotid artery by angiogram

3. Target vessel must meet all requirements for ENROUTE Transcarotid Neuroprotection System and ENROUTE Stent System (refer to IFU for requirements).
4. Patient is ≥18 and <80 years of age.
5. 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 Institutional Review Board of the respective clinical site prior to the study procedure. This will be obtained prior to participation in the study.
6. Patient is willing to comply with the protocol requirements and return to the treatment center for all required clinical evaluations.

Exclusion Criteria:

1. Patient meets any of the surgical high-risk criteria listed below.

   1. Anatomic high risk exclusion criteria:

      • Contralateral carotid artery occlusion
      • Tandem stenoses in the ICA >70% diameter reducing
      • High cervical carotid artery stenosis above the C2 vertebra
      • Restenosis after prior ipsilateral carotid endarterectomy
      • Bilateral carotid artery stenosis requiring treatment within 30 days after index procedure
      • Hostile Necks including prior neck irradiation, radical neck dissection, and cervical spine immobility

   2. Clinical high risk exclusion criteria:

      • Patient is ≥80 years of age
      • Patient has ≥2-vessel coronary artery disease (or has had revascularization procedure within the last 30 days) and/or angina
      • Patient has history of unresolved angina - Canadian Cardiovascular Society (CCS) angina class 3 or 4 OR unstable angina
      • Patient has congestive heart failure (CHF) - New York Heart Association (NYHA) Functional Class III or IV
      • Patient has a known severe left ventricular dysfunction - LVEF <30%
      • Patient has had a myocardial infarction within 6 weeks prior to the procedure

      • Patient has severe obstructive pulmonary disease (COPD) with either:

        • FEVI <50% predicted OR
        • chronic oxygen therapy OR
        • resting PO2 of ≤60 mmHG (room air)
      • Patient has permanent contralateral cranial and/or laryngeal nerve injury
      • Patient has chronic renal insufficiency (serum creatinine ≥2.5 mg/dL) or is on dialysis

2. Patient has an alternative source of cerebral embolus, including but not limited to:

   1. Chronic atrial fibrillation.
   2. Any episode of paroxysmal atrial fibrillation within the past 6 months, or history of paroxysmal atrial fibrillation requiring chronic anticoagulation.
   3. Knowledge of cardiac sources of thrombus. (If patient has 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 AND there is no confirmed thrombus on an echocardiogram performed within 3 months prior to index procedure, the patient may be eligible for enrollment).
   4. Recently implanted heart valve (either surgically or endovascularly) within 60 days prior to index procedure with confirmed emboli on echocardiogram.
   5. Abnormal angiographic findings: ipsilateral intracranial or extracranial arterial stenosis (as determined by pre-procedure angiography or CTA/MRA ≤6 months prior to index procedure) 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.
3. Patient has a history of spontaneous intracranial hemorrhage within the past 12 months or 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.
4. Patient had hemorrhagic transformation of an ischemic stroke within the past 60 days.
5. Patient with a history of major stroke prior to the TCAR procedure attributable to either carotid artery (CVA or retinal embolus) with major neurological deficit (NIHSS ≥5 OR mRS ≥3) likely to confound study endpoints 1 month after the TCAR procedure (because the deficit persists post-operatively).
6. Patient has an intracranial tumor.
7. Patient has an evolving stroke.
8. Patient has neurologic illnesses within the past 2 years characterized by fleeting or fixed neurologic deficit which cannot be distinguished from TIA or stroke, including but not limited to: moderate to severe dementia, 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, or intracranial hemorrhage.
9. Patient has had a TIA or amaurosis fugax within 48 hrs. prior to the procedure
10. Patient has an isolated hemisphere
11. Patient had or will have open heart (e.g., CABG), endovascular stent procedure, valve intervention, vascular surgery, other major operation within 30 days of the index procedure.
12. Presence of a previous placed intravascular stent in target vessel or ipsilateral CCA or significant CCA inflow lesion.
13. Occlusion or [Thrombolysis in Myocardial Infarction Trial (TIMI 0)] "string sign" >1cm of the ipsilateral common or internal carotid artery.
14. 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) whether or not it is associated with an ulcerated target lesion.
15. Ostium of CCA requires revascularization.
16. Patient has an open stoma in the neck.
17. Female patients who are pregnant or may become pregnant.
18. Patient has history of intolerance or allergic reaction to any of the study medications or stent materials (refer to ENROUTE stent IFU), including aspirin (ASA), ticlopidine, clopidogrel, statin or contrast media (that cannot be pre-medicated). Patients must be able to tolerate statins (or a permitted non-statin substitute) and a combination of ASA and ticlopidine or ASA and clopidogrel or alternative P2Y12 inhibitor..
19. Patient has a life expectancy <5 years without contingencies related to other medical, surgical, or interventional procedures or is at High Risk as per the Wallaert Score. Estimation of life expectancy and scoring per the Wallaert Score is to be performed prior to enrollment.
20. Patient has primary, recurrent or metastatic malignancy and does not have independent assessment of life expectancy of ≥5 years performed by the treating oncologist or an appropriate specialist other than the physician performing TCAR.
21. Patient has an unresolved/uncorrected bleeding disorder.
22. Patient has a known allergy to nitinol
23. Patient is known to have an active SARS-CoV-2 infection (Coronavirus-19 [COVID-19]) or has been previously diagnosed with COVID-19 with neurological sequelae that could confound endpoint assessments (e.g., baseline mRS>3).

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Standard-risk patients requiring carotid intervention; Symptomatic or asymptomatic patients with a discrete lesion located in the internal carotid artery (ICA) with or without involvement of the contiguous common carotid artery (CCA), who require carotid artery revascularization.	Procedure: Transcarotid Artery Revascularization (TCAR); Carotid artery revascularization treated with the FDA-cleared ENROUTE Transcarotid NPS in conjunction with the FDA-approved ENROUTE Transcarotid Stent; Other Names: Carotid Artery Stenting; Carotid Revascularization

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hierarchical composite of Major Adverse Events (MAEs)	Hierarchical composite of Major Adverse Events (MAEs) defined as any death, stroke, or myocardial infarction within 30 days of the index procedure	within 30 days of the index procedure
Ipsilateral Stroke	Ipsilateral stroke within 31 days to 365 days following the index procedure	within 31 to 365 days following the index procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of cranial nerve injury	Incidence of cranial nerve injury within 30 days of the index procedure	within 30 days of the index procedure
Stroke	Stroke within 30 days of the index procedure	within 30 days of the index procedure
Death	Death within 30 days of the index procedure	within 30 days of the index procedure
MI	MI within 30 days of the index procedure	within 30 days of the index procedure
Stroke/Death/MI	Stroke/Death/MI within 30 days of the index procedure	within 30 days of the index procedure
Persistent cranial nerve injury	Persistent cranial nerve injury at 6 months and 1 year	at 6 months and 1 year
Rate of hierarchical ipsilateral stroke, death, and myocardial infarction	Rate of hierarchical ipsilateral stroke, death, and myocardial infarction within 30 days of the index procedure	within 30 days of the index procedure
Cardiac death	Cardiac death at 1 year for patients who experienced an MI within 30 days of the index procedure	1 year
Access site complications	Access site complications (arterial/venous)	within 30 days of the index procedure
Serious Hematoma/Bleeding complications	Serious Hematoma/Bleeding complications (arterial/venous)	within 30 days of the index procedure
Rate of stent thrombosis or occlusion	Rate of stent thrombosis or occlusion within 30 days of the index procedure	within 30 days of the index procedure
Rate of dissection	Rate of dissection within 30 days of the index procedure (during index procedure or a reintervention procedure)	within 30 days of the index procedure
Ipsilateral Stroke	Ipsilateral stroke within 31 to 365 days of the index procedure	31-365 days

Collaborators and Investigators

• Sponsor: Silk Road Medical
• Investigators: Principal Investigator: Meghan Dermody, MD, Lancaster General Hospital; Principal Investigator: Jeffrey Jim, MD, Abbott Northwestern Minneapolis Heart Institute Foundation; Principal Investigator: Marc Schermerhorn, MD, Beth Israel Deaconess Medical Center

Publications and helpful links

General Publications

• Vilain KR, Magnuson EA, Li H, Clark WM, Begg RJ, Sam AD 2nd, Sternbergh WC 3rd, Weaver FA, Gray WA, Voeks JH, Brott TG, Cohen DJ; CREST Investigators. Costs and cost-effectiveness of carotid stenting versus endarterectomy for patients at standard surgical risk: results from the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST). Stroke. 2012 Sep;43(9):2408-16. doi: 10.1161/STROKEAHA.112.661355. Epub 2012 Jul 19.
• Malas MB, Dakour-Aridi H, Kashyap VS, Eldrup-Jorgensen J, Wang GJ, Motaganahalli RL, Cronenwett JL, Schermerhorn ML. TransCarotid Revascularization With Dynamic Flow Reversal Versus Carotid Endarterectomy in the Vascular Quality Initiative Surveillance Project. Ann Surg. 2022 Aug 1;276(2):398-403. doi: 10.1097/SLA.0000000000004496. Epub 2020 Sep 15.
• Schermerhorn ML, Liang P, Eldrup-Jorgensen J, Cronenwett JL, Nolan BW, Kashyap VS, Wang GJ, Motaganahalli RL, Malas MB. Association of Transcarotid Artery Revascularization vs Transfemoral Carotid Artery Stenting With Stroke or Death Among Patients With Carotid Artery Stenosis. JAMA. 2019 Dec 17;322(23):2313-2322. doi: 10.1001/jama.2019.18441.

Helpful Links

• Description: Peri-procedural Outcomes After Carotid Artery Stenting with the First 15,000 Patients Enrolled in the SAPPHIRE Worldwide Study.

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2022
• Primary Completion (Actual): July 22, 2025
• Study Completion (Actual): July 22, 2025

Study Registration Dates

• First Submitted: May 3, 2022
• First Submitted That Met QC Criteria: May 6, 2022
• First Posted (Actual): May 9, 2022

Study Record Updates

• Last Update Posted (Actual): July 30, 2025
• Last Update Submitted That Met QC Criteria: July 27, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Carotid Artery Diseases
• Other Study ID Numbers: SRM-2022-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Not planning to share IPD

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No