Skip to main content
OpenTrials
Recruiting

NCT Number: NCT07228312

A Study of Choydar Flow-Directed Mesh Stent in the Treatment of Unruptured Intracranial Aneurysms

The purpose of this study is to assess how safe choydar flow-directed mesh stent is and how well it works in the treatment of unruptured intracranial aneurysms (a condition in which a bulging blood vessel in the brain can burst and cause bleeding) in a real-world setting.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Intracranial Aneurysm Aneurysm Brain Diseases Cardiovascular Diseases Central Nervous System Diseases Cerebrovascular Disorders Intracranial Arterial Diseases Nervous System Diseases Vascular Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Chenzhou No.1 People's Hospital, Chenzhou, China

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Participants meeting all the following inclusion criteria will be included:

Preoperative inclusion criteria:

  • Presence of unruptured aneurysms in the internal carotid artery (from the petrous segment to the distal end) or vertebral artery identified by digital subtraction angiography (DSA), computed tomography angiography (CTA), or magnetic resonance angiography (MRA) prior to surgery, wide-neck (neck width greater than or equal to [>=] 4 millimeters [mm] or dome-to-neck ratio less than [<] 2) saccular or fusiform aneurysms, and the parent artery diameter must be >= 2.0 mm and less than or equal to [<=] 6.0 mm
  • Participants and/or their authorized representatives understand the purpose of the study, and are willing to voluntarily participate in the study and sign the informed consent form (ICF)
  • Prior to enrollment, a clinical decision has already been made to use the choydar flow-directed mesh stent
  • Participants who are willing and able to return for all follow-up visits as required by the study protocol

Intraoperative inclusion criteria:

  • Presence of unruptured aneurysms in the internal carotid artery (from the petrous segment to the distal end) or vertebral artery identified by DSA during the procedure, wide-neck (neck width >= 4 mm or dome-to-neck ratio <2) saccular or fusiform aneurysms, and the parent artery diameter must be >= 2.0 mm and <= 6.0 mm

Exclusion criteria

Participants meeting any of the following exclusion criteria will be excluded:

  • Participants with anatomy are unsuitable for flow diverter passage or placement or lesions unsuitable for flow diverter delivery and deployment (for example, the lesion vessel is excessively tortuous or tiny, the flow diverter cannot reach the lesion site, stenosis exists in the target vessel of recurrent aneurysm, or the flow diverter is not completely deployed)
  • Participants who are allergic to contrast media
  • Participants who are allergic to nickel-titanium alloy or platinum-tungsten alloy
  • Participants who are contraindicated for antiplatelet and/or anticoagulant therapy
  • Participants with active bacterial infections
  • Participants who are confirmed positive pregnancy (for example, via test or oral communication) according to the site-specific standard of care
  • Participants who are currently participating in an investigational (drug, device, etc.) clinical study that may confound the study endpoints (excluding observational, natural history, and/or epidemiological studies that do not require interventions)

Treatment and study plan

Primary outcomes

  1. Complete Aneurysm Occlusion Rate at 12 Months Post-Procedure (Raymond-Roy Class I)

    Time frame: At 12 months follow-up post-procedure

    Complete aneurysm occlusion rate as per Raymond Roy classification criteria (Class I) is defined as complete obliteration (no contrast filling in aneurysm body or neck). It is calculated as follows: number of target aneurysms achieving Raymond-Roy Class I occlusion at 12-month follow-up post-procedure/number of target aneurysms with 12-month imaging evaluation * 100 percent (%).

  2. Adequate Aneurysm Occlusion Rate at 12-month Follow-up Post-Procedure (Raymond-Roy Classes I and II)

    Time frame: At 12 months follow-up post-procedure

    Adequate aneurysm occlusion rate as per Raymond Roy classification criteria (Class II and III) is defined as Class II: residual neck (contrast filling in aneurysm neck but none in aneurysm body) and Class III: residual aneurysm (contrast filling in aneurysm body). It is calculated as follows: number of target aneurysms achieving Raymond-Roy Class I/II occlusion at 12-month follow-up post-procedure/number of target aneurysms with 12-month imaging evaluation * 100 %.

  3. Percentage of Participants with Immediate Technical Success Rate of Procedure

    Time frame: At Day 0 (Day of procedure)

    Percentage of participants with immediate technical success rate of procedure will be reported. Immediate technical success of the procedure is defined as the percentage of participants in whom the flow diverter is successfully deployed during the procedure, with accurate positioning confirmed by intra-procedure angiography, and with effective coverage of the aneurysm neck by the implant. It is calculated as follows: number of participants with successful placement of the investigational device/total number of participants undergoing the treatment * 100 %.

  4. Re-treatment Rate of Target Aneurysm at 12-Month Follow-up Post-Procedure

    Time frame: At 12 months follow-up post-procedure

    The incidence of re-treatment of the target aneurysm at 12 months follow-up post-procedure will be reported.

  5. Percentage of Participants with Modified Rankin Scale (mRS) Score of 0-2 at 12 Months Post-Procedure

    Time frame: At 12 months follow-up post-procedure

    Percentage of participants with mRS score of 0-2 at 12 months post-procedure will be reported. The mRS score is issued to evaluate the improvement of neurological function. It assesses the ability of participants with neurological disease to live independently. There are 7 levels of this score, 0 points represent no symptoms of disability, higher scores mean worse prognosis of participants , and 6 points represent death.

  6. Number of Participants with Major Ischemic/Hemorrhagic Events and/or Death During Perioperative Period

    Time frame: Perioperative

    Number of participants with major ischemic/hemorrhagic events and/or death during perioperative period will be reported. Major ischemic/hemorrhagic events are defined as an increase of >= 4 points in the National Institutes of Health Stroke Scale (NIHSS) score compared with the previous score.

  7. Number of Participants with Major Ischemic/Hemorrhagic Events and/or Death During 12-Month Follow-up

    Time frame: At 12 months follow-up post-procedure

    Number of participants with major ischemic/hemorrhagic events and/or death during 12 months follow-up period will be reported. Major ischemic/hemorrhagic events are defined as an increase of >= 4 points in the NIHSS score compared with the previous score.

  8. Number of Participants with Severe in-Stent Stenosis (Greater Than [>] 50%) During 12-Month Follow-up

    Time frame: At 12 months follow-up post-procedure

    Number of participants with severe in-stent stenosis during 12-month follow-up period will be reported. The percent stenosis is calculated according to the calculation method of Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) study as follows: (1 - Ds [Diameter of the artery at the site of the most severe stenosis]/Dn [Diameter of the normal artery]) * 100%.

  9. Rupture Rate of Target Aneurysm During 12-Month Follow-Up Post-Procedure

    Time frame: At 12 months follow-up post-procedure

    The incidence of rupture of the target aneurysm within 12 months post-procedure will be reported.

Study contacts

Contact information is provided by the study sponsor or research team.

Yuanyuan Gu

CONTACT

[email protected]

86 15692105615

Sponsors and collaborators

Lead sponsor

Johnson & Johnson Medical (Shanghai) Ltd.

Industry

Registry information

Official study title

A Multicenter, Prospective, Single-Arm Observational Study to Evaluate the Safety and Effectiveness of the Choydar Flow-Directed Mesh Stent in the Treatment of Unruptured Intracranial Aneurysms

Acronym: CROWN

Important dates

Study start
2026
Primary completion
2028
Study completion
2028
First posted
Nov 14, 2025
Registry last updated
Jul 6, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.