International Registry of Intra-arterial and Endosaccular Flow Diverters (IRF) (IRF)

January 5, 2026 updated by: Montefiore Medical Center

Outcomes of Intra-arterial and Endosaccular Flow Diverters for Treatment of Intracranial Aneurysms - International Registry of Intra-arterial and Endosaccular Flow Diverters (IRF)

This multicenter retrospective cohort study aims to evaluate and compare the technical performance, safety, and clinical outcomes of intracranial aneurysms treated with flow diverter stents and endosaccular flow disruptors.

Study Overview

Status

Recruiting

Conditions

Detailed Description

Flow diverters and endosaccular flow disruptors used for the treatment of intracranial aneurysms exhibit distinct procedural and clinical outcomes, with potential differences in device-specific parameters such as procedure time, radiation exposure, adjunct device requirements, and long-term angiographic success. Since the completion of the Pipeline Embolization Device (PED) for the Intracranial Treatment of Aneurysms trial, the field of flow diversion has undergone continuous evolution with the development and approval of several devices. While these devices share a similar mechanism for aneurysm occlusion, their design and delivery systems can vary significantly. Various studies have demonstrated a promising safety and efficacy profile; however, the available data for a direct comparison of the technical and clinical outcomes between these devices remains limited.

Study Type

Observational

Enrollment (Estimated)

5000

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Canada
    • Ontario
      • Toronto, Ontario, Canada, M5T 2S8
        • Recruiting
        • Toronto Western Hospital
        • Contact:
  • United States
    • Florida
      • Coral Gables, Florida, United States, 33146
        • Recruiting
        • University of Miami
        • Contact:
      • Jacksonville, Florida, United States, 32224
        • Completed
        • Mayo Clinic Florida
      • Sarasota, Florida, United States, 34239
        • Recruiting
        • Sarasota Memorial Research Institute
        • Contact:
    • Massachusetts
      • Burlington, Massachusetts, United States, 01805
        • Recruiting
        • Lahey Hospital and Medical Center
        • Contact:
    • Michigan
      • Traverse City, Michigan, United States, 49684
        • Recruiting
        • Munson Medical Center
        • Contact:
    • New Jersey
      • New Brunswick, New Jersey, United States, 08901
        • Recruiting
        • Robert Wood Johnson University
        • Contact:
    • New York
      • Buffalo, New York, United States, 14068
        • Completed
        • University at Buffalo
      • The Bronx, New York, United States, 10467
        • Recruiting
        • Montefiore Medical Center Department of Neurosurgery
        • Principal Investigator:
          • David Altschul, MD
        • Contact:
        • Contact:
    • Pennsylvania
      • Danville, Pennsylvania, United States, 17822
        • Completed
        • Geisinger Health
    • Texas
      • Kingwood, Texas, United States, 77339
        • Completed
        • HCA Houston Healthcare Kingwood

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients with intracranial aneurysms who underwent endovascular treatment with flow diverter stents or endosaccular flow disruptors

Description

Inclusion Criteria:

  • Adult patients (18 years of age or older)

  • Underwent endovascular treatment with one of the following devices:

    a. Endoluminal Flow Diverter Stents: i. Pipeline Flex (Covidien, California, USA) ii. Pipeline Flex with Shield Technology (Covidien) iii. Surpass Streamline (Stryker Neurovascular, California, USA) iv. Surpass Evolve (Stryker) v. Silk flow diverter (Balt Extrusion, Montmorency, France) vi. Flow-Redirection Intraluminal Device (FRED; MicroVention) vii. Flow-Redirection Intraluminal Device X (FRED X; MicroVention) viii. p64 Flow Modulation Device (phenox GmbH) ix. Endovascular clip system (eCLIPs) (eCLIPsTM, eVasc Neurovascular, Vancouver, BC, Canada)

    b. Intrasaccular Flow Disruptors: i. Woven EndoBridge (WEB; MicroVention) ii. Luna/Artisse System (Medtronic) iii. Medina Embolic Device (Medtronic) iv. Contour Neurovascular System (Cerus Endovascular) v. Neqstent Coil Assisted Flow Diverter (Cerus Endovascular) vi. pCONus and pCANvas (phenox GmbH) vii. Nexus Aneurysm Embolization System (EndoStream Medical) viii. CITADEL™ Embolization Device (Balt, USA)

  • Complete medical records and follow-up data available

Exclusion Criteria:

  • Incomplete procedural or follow-up records
  • Non-flow-diverter or non-flow-disruptor treatments (e.g., coiling-only cases)
  • Aneurysms treated with investigational devices not listed within Inclusion Criteria

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Procedural Complications following placement
Time Frame: From the time of the procedure up to 1 month post treatment
Procedural complications will be identified as the number of instances of the following adverse clinical events: In-stent Thrombosis/Stenosis; Ischemic complications (Transient Ischemic Attack/Stroke), Intracerebral hemorrhage, Aneurysm rupture, and Vessel occlusion due to flow diverter stent or endosaccular flow disruptor placement.
From the time of the procedure up to 1 month post treatment
Clinical Outcomes at Discharge
Time Frame: Upon study discharge, up to 4 weeks
Clinical outcomes at discharge will be assessed using the modified Rankin Scale (mRS) for neurologic disability. The mRS is a 6-point disability scale with possible scores ranging from 0-5. mRS measures the degree of disability or dependence in the daily activities of people who have suffered a stroke or other causes of neurological disability. Higher scores are generally associated with less favorable outcomes. For this study patients with an mRS score of 0-2 will be determined to have had a "favorable" outcome to the procedure and patients with an mRS score of 3-5 will have been determined to have had an "unfavorable" outcome.
Upon study discharge, up to 4 weeks
Clinical Outcomes at last available Follow-up
Time Frame: Up to 24 months post procedure
Clinical outcomes at last available follow-up will be assessed using a variant of the modified Rankin Scale (mRS) for neurologic disability. The classic mRS is a 6-point disability scale with possible scores ranging from 0-5. mRS measures the degree of disability or dependence in the daily activities of people who have suffered a stroke or other causes of neurological disability. Higher scores are generally associated with less favorable outcomes. For this study patients with an mRS score of 0-2 will be determined to have had a "favorable" outcome to the procedure and patients with an mRS score of 3-5 will have been determined to have had an "unfavorable" outcome. Scoring will also include a 6 to identify patients who have expired.
Up to 24 months post procedure
Immediate Angiographic Outcomes at Discharge - O'Kelly-Marotta (OKM) grading scale
Time Frame: Upon study discharge, up to 4 weeks
Immediate Angiographic Outcomes at Discharge will be evaluated using the OKM grading scale. The OKM scale will be used to assess the degree of angiographic filling and in the setting of intracranial aneurysms which were treated by endovascular flow diversion. It is used to predict aneurysm closure over time. Patient outcomes will be stratified based on the following scale scores: Grade A: Total filling (>95% of aneurysm remained); Grade B: Subtotal filling (5-95% of aneurysm remained); Grade C: Entry remnant (<5% aneurysm remained); and Grade D: No filling (0% aneurysm remained). As such, the less aneurysm remnant the more favorable the angiographic outcome. The number/percentage of cases of each OKM Grade will be summarized.
Upon study discharge, up to 4 weeks
Immediate Angiographic Outcomes at Discharge - Modified Raymond-Roy Classification (mRRC)
Time Frame: Upon study discharge, up to 4 weeks
Immediate Angiographic Outcomes at Discharge will also be evaluated using mRRC categorization. mRRC categorization will be used to assess the degree of occlusion achieved when treating an intracranial aneurysm. It categorizes the level of residual contrast filling within an aneurysm after coiling. For purposes of this analysis, Class I will signify complete occlusion; Class II will signify Residual neck occlusion; Class IIIa will signify Residual aneurysm with contrast stasis; and Class IIIb will signify Residual aneurysm without contrast stasis. As such, it is an indicator of how effectively the aneurysm has been sealed off during treatment. The number/percentage of cases of each mRRC category will be summarized.
Upon study discharge, up to 4 weeks
Immediate Angiographic Outcomes at Discharge - WEB Occlusion Scale (WOS)
Time Frame: Upon study discharge, up to 4 weeks
Immediate Angiographic Outcomes at Discharge will be evaluated using the WOS grading scale. The WOS is a standardized angiographic assessment scale for reporting aneurysm occlusion achieved with endosaccular flow disruptors and can be employed to assess the adequacy of treatment. For purposes of this analysis, WOS Grade A will signify complete occlusion; WOS Grade B will signify Residual neck occlusion; and WOS Grade C will signify Residual aneurysm filling. The number/percentage of cases of each WOS grade category will be summarized.
Upon study discharge, up to 4 weeks
Angiographic Outcomes at last available Follow-up - O'Kelly-Marotta (OKM) grading scale
Time Frame: Up to 24 months post procedure
Immediate Angiographic Outcomes at Discharge will be evaluated using the OKM grading scale. The OKM scale will be used to assess the degree of angiographic filling and in the setting of intracranial aneurysms which were treated by endovascular flow diversion. It is used to predict aneurysm closure over time. Patient outcomes will be stratified based on the following scale scores: Grade A: Total filling (>95% of aneurysm remained); Grade B: Subtotal filling (5-95% of aneurysm remained); Grade C: Entry remnant (<5% aneurysm remained); and Grade D: No filling (0% aneurysm remained). As such, the less aneurysm remnant the more favorable the angiographic outcome. The number/percentage of cases of each OKM Grade will be summarized.
Up to 24 months post procedure
Angiographic Outcomes at last available Follow-up - Modified Raymond-Roy Classification (mRRC)
Time Frame: Up to 24 months post procedure
Immediate Angiographic Outcomes at Discharge will also be evaluated using mRRC categorization. mRRC categorization will be used to assess the degree of occlusion achieved when treating an intracranial aneurysm. It categorizes the level of residual contrast filling within an aneurysm after coiling. For purposes of this analysis, Class I will signify complete occlusion; Class II will signify Residual neck occlusion; Class IIIa will signify Residual aneurysm with contrast stasis; and Class IIIb will signify Residual aneurysm without contrast stasis. As such, it is an indicator of how effectively the aneurysm has been sealed off during treatment. The number/percentage of cases of each mRRC category will be summarized.
Up to 24 months post procedure
Angiographic Outcomes at last available Follow-up - WEB Occlusion Scale (WOS)
Time Frame: Up to 24 months post procedure
Immediate Angiographic Outcomes at Discharge will be evaluated using the WOS grading scale. The WOS is a standardized angiographic assessment scale for reporting aneurysm occlusion achieved with endosaccular flow disruptors and can be employed to assess the adequacy of treatment. For purposes of this analysis, WOS Grade A will signify complete occlusion; WOS Grade B will signify Residual neck occlusion; and WOS Grade C will signify Residual aneurysm filling. The number/percentage of cases of each WOS grade category will be summarized.
Up to 24 months post procedure
Technical Success
Time Frame: Periprocedurally, up to 24 hours
Technical Success will be determined by successful deployment of the flow diverter stent or endosaccular flow disruptors. A dichotomous determination (i.e., Yes/No) will be made and summarized for this study.
Periprocedurally, up to 24 hours

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Radiation Exposure
Time Frame: Periprocedurally, up to 4 hours
Radiation exposure over the course of the procedure will be extracted and summarized. Radiation exposure will be evaluated based on relevant imaging system metrics used to calculate the total radiation dose delivered to the patient based on the fluoroscopy time and the area of the X-ray field exposed during the procedure. Flow diverter stents and endosaccular flow disruptors typically result in significantly lower radiation exposure compared to other endovascular techniques for treating brain aneurysms due to a reduction in fluoroscopy time and overall reduced radiation dose due to the streamlined nature of the procedures.
Periprocedurally, up to 4 hours
Procedure Duration
Time Frame: Periprocedurally, up to 4 hours
The duration of procedure placement will be extracted and summarized. The duration of the procedure is influenced by the complexity of the aneurysm, the patient's anatomy, and the experience of the interventional radiologist and care team. Shorter procedure duration times are associated with more favorable outcomes.
Periprocedurally, up to 4 hours
Use of Adjunct Devices
Time Frame: Periprocedurally, up to 4 hours
The use of adjunctive devices such as coils, stents or balloons to further enhance aneurysm occlusion of the flow diverter stent or to facilitate positioning and deployment of the endosaccular flow disruptor within the aneurysm sac during the procedure will be extracted and summarized. The number of adjunct devices will be extracted and summarized.
Periprocedurally, up to 4 hours
Recurrence of Aneurysm
Time Frame: 6 to 24 months post procedure
The percentage of patients who experienced aneurysm recurrence will be extracted and summarized based on a binary (Yes/No) determination following retrospective record review. The span of time from initial treatment to recurrence will be assessed and summarized.
6 to 24 months post procedure
Aneurysm Retreatment
Time Frame: 6 to 24 months post procedure
The percentage of patients who required retreatment for a recurrence of aneurysm will be extracted and summarized based on a binary (Yes/No) determination following retrospective record review. The span of time from initial treatment to retreatment will be assessed and summarized.
6 to 24 months post procedure

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Montefiore Medical Center

Collaborators

Mayo Clinic
University at Buffalo
Thomas Jefferson University
Geisinger Health
Simpson Memorial Research Institute

Investigators

  • Principal Investigator: David Altschul, MD, Montefiore Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 1, 2023

Primary Completion (Estimated)

June 1, 2026

Study Completion (Estimated)

June 1, 2026

Study Registration Dates

First Submitted

December 5, 2023

First Submitted That Met QC Criteria

December 13, 2023

First Posted (Actual)

December 18, 2023

Study Record Updates

Last Update Posted (Actual)

January 7, 2026

Last Update Submitted That Met QC Criteria

January 5, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2023-15177

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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