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

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

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.

Study Overview

• Status: Recruiting
• Conditions: Intracranial Aneurysm

• Study Type: Observational
• Enrollment (Estimated): 200

Contacts and Locations

• Study Contact: Name: Yuanyuan Gu; Phone Number: 86 15692105615; Email: ygu51@its.jnj.com

Study Locations

• China
  • Guangzhou, China, 519041
    • Recruiting
    • Guangdong Provincial People's Hospital
  • Nanjing, China, 210008
    • Recruiting
    • Nanjing Drum Tower Hospital The Affiliated Hospital of Nanjing University Medical School
  • Zhengzhou, China, 450052
    • Recruiting
    • The First Affiliated Hospital of Zhengzhou University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult participants with unruptured wide-neck (neck width >= 4 mm or dome-to-neck ratio <2) saccular or fusiform aneurysms in the internal carotid artery (from the petrous segment to the distal end) and the vertebral artery arising from a parent vessel with a diameter >= 2.0 mm and <= 6.0 mm.

Description

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)

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Choydar Flow-Directed Mesh Stent; The choydar flow-directed mesh stent will be used in accordance to its Instructions For Use (IFU) in participants with unruptured intracranial aneurysms. Participants will not receive any other intervention as a part of this study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Complete Aneurysm Occlusion Rate at 12 Months Post-Procedure (Raymond-Roy Class I)	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 (%).	At 12 months follow-up post-procedure
Adequate Aneurysm Occlusion Rate at 12-month Follow-up Post-Procedure (Raymond-Roy Classes I and II)	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 %.	At 12 months follow-up post-procedure
Percentage of Participants with Immediate Technical Success Rate 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 %.	At Day 0 (Day of procedure)
Re-treatment Rate of Target Aneurysm at 12-Month Follow-up Post-Procedure	The incidence of re-treatment of the target aneurysm at 12 months follow-up post-procedure will be reported.	At 12 months follow-up post-procedure
Percentage of Participants with Modified Rankin Scale (mRS) Score of 0-2 at 12 Months 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.	At 12 months follow-up post-procedure
Number of Participants with Major Ischemic/Hemorrhagic Events and/or Death During Perioperative Period	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.	Perioperative
Number of Participants with Major Ischemic/Hemorrhagic Events and/or Death During 12-Month Follow-up	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.	At 12 months follow-up post-procedure
Number of Participants with Severe in-Stent Stenosis (Greater Than [>] 50%) During 12-Month Follow-up	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%.	At 12 months follow-up post-procedure
Rupture Rate of Target Aneurysm During 12-Month Follow-Up Post-Procedure	The incidence of rupture of the target aneurysm within 12 months post-procedure will be reported.	At 12 months follow-up post-procedure

Collaborators and Investigators

• Sponsor: Johnson & Johnson Medical (Shanghai) Ltd.
• Investigators: Study Director: Johnson & Johnson Medical (Shanghai) Ltd. Clinical Trial, Johnson & Johnson Medical (Shanghai) Ltd.

Study record dates

Study Major Dates

• Study Start (Actual): January 28, 2026
• Primary Completion (Estimated): February 10, 2028
• Study Completion (Estimated): February 10, 2028

Study Registration Dates

• First Submitted: November 13, 2025
• First Submitted That Met QC Criteria: November 13, 2025
• First Posted (Actual): November 14, 2025

Study Record Updates

• Last Update Posted (Actual): June 5, 2026
• Last Update Submitted That Met QC Criteria: June 4, 2026
• Last Verified: June 1, 2026

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; Intracranial Arterial Diseases; Aneurysm; Intracranial Aneurysm
• Other Study ID Numbers: CNV202507 (DePuy Synthes Products, Inc)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The data sharing policy of Johnson & Johnson MedTech is available at www.innovativemedicine.jnj.com/our-innovation/clinical-trials/transparency. As noted on this site, requests for access to the study data can be submitted through Yale Open Data Access (YODA) Project site at yoda.yale.edu.

Drug and device information, study documents

• Studies a U.S. FDA-regulated device product: No