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Effects of Carotid Stent Design on Cerebral Embolization

This study has been completed.
Information provided by (Responsible Party):
Carlos H. Timaran, Dallas VA Medical Center Identifier:
First received: January 26, 2009
Last updated: August 1, 2016
Last verified: August 2016
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).

Condition Intervention
Carotid Stenosis
Device: closed-cell stent
Device: Open-cell stent

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Effects of Carotid Stent Design on Cerebral Embolization

Further study details as provided by Dallas VA Medical Center:

Primary Outcome Measures:
  • Transcranial Doppler Counts of Micro-embolic Signals in the Ipsilateral Middle Cerebral Artery. [ Time Frame: First 24 hours after implantation of carotid stent ]
    Bilateral transcranial Doppler scan monitoring of the anterior and middle cerebral arteries was performed using a PMD150-ST3 digital transcranial Doppler pulsed-wave ultrasound scan system (Spencer Technologies, Seattle, Wash) with 2-MHz probes located over the temporal bones above the zygomatic arch. Isolated microembolic signals (MES) were identified from Doppler spectras according to the criteria given by the Consensus Committee of the Ninth International Cerebral Hemodynamic Symposium. If the number of MES was too high to be counted separately, heartbeats with microemboli were counted as microembolic showers. To avoid confusion, MES detected during contrast injection were excluded from the analysis. For analysis purposes, the procedure was divided into the following phases: lesion crossing, filter deployment, IVUS examination, predilation, stent deployment, postdilatation (when applicable), and filter removal.

Secondary Outcome Measures:
  • Composite of Any Stroke, Myocardial Infarction or Death [ Time Frame: within 30 days after the carotid stenting procedure ]
  • Subclinical Cerebral Embolization Assessed by Brain Diffusion-weighted MRI [ Time Frame: within 24 hours after carotid artery stenting ]

Enrollment: 40
Study Start Date: December 2008
Study Completion Date: February 2012
Primary Completion Date: December 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Closed-cell stent Device: closed-cell stent

Patients enrolled in this study arm underwent for carotid stenting using closed stent cell. The graft used in this groups was the Xact closed-cell stent. This type of device is rigid device with dense conposition of the nitinol rigns.

Carotid stenting was used on standard fashion using filters as embolic protection device.

Other Name: Carotid artery angioplasty
Active Comparator: Open-cell stent Device: Open-cell stent

Patients enrolled in this study arm underwent for carotid stenting using open stent cell stents. This type of stent is a tube shaped graft composed of flexible nitinol rings. The device used in this group was the Acculinx open-cell stent.

Stenting procedure eas performed on standard fashion.Filters were used as embolic protection device.

Other Name: Carotid artery angioplasty

Detailed Description:

Stroke is responsible for more than 10% of all deaths and much severe disability in developed countries. In the United States, approximately 600,000 new strokes are reported annually, of which 150,000 are fatal, and more than 4,000,000 surviving stroke victims are affected by significant disability. Seventy-five percent of strokes occur in the distribution of the carotid arteries and are considered of a thromboembolic etiology, most of which originate in carotid lesions. Carotid artery stenting (CAS) with cerebral embolic protection is currently the preferred treatment of carotid stenosis in high risk surgical patients, i.e., those with significant comorbidities or a hostile neck from previous surgical procedures or radiation. Although several predictors of adverse outcomes after CAS have been identified, the effects of device characteristics, including stent design, on neurologic adverse events have not been established.

The proposed study will be a randomized prospective controlled trial designed to test the hypothesis that the implantation of closed-cell stents for carotid lesions in high-risk patients will be associated with a reduced perioperative cerebral microembolization, as detected by transcranial Doppler and diffusion-weighted magnetic resonance imaging of the brain, and reduced 30-day stroke, myocardial infarction, and death rates when compared with the implantation of open-cell stents.


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

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.
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Please refer to this study by its identifier: NCT00830232

United States, Texas
Dallas VA Medical Center
Dallas, Texas, United States, 75216
Sponsors and Collaborators
Dallas VA Medical Center
Principal Investigator: Carlos H Timaran, MD Dallas VA Medical Center
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Carlos H. Timaran, Vascular and Endovascular Surgeon, Dallas VA Medical Center Identifier: NCT00830232     History of Changes
Other Study ID Numbers: IRB#08-035
Study First Received: January 26, 2009
Results First Received: March 8, 2013
Last Updated: August 1, 2016

Keywords provided by Dallas VA Medical Center:
Carotid stenosis

Additional relevant MeSH terms:
Carotid Stenosis
Carotid Artery Diseases
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Arterial Occlusive Diseases
Vascular Diseases
Cardiovascular Diseases processed this record on April 24, 2017