An observational study in Iliofemoral Vein Stenosis and Iliofemoral Vein Occlusion, sponsored by Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-09.
Sponsored by Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine · Observational
This multi-center, real-world observational study is being conducted at five hospitals in China to evaluate the effectiveness of the Vflower venous stent system in patients with iliofemoral vein stenosis or occlusion. Iliofemoral vein stenosis or occlusion occurs when the large veins in the pelvis or thigh become narrowed or blocked, which can cause leg swelling, pain, varicose veins, skin changes, and in severe cases, non-healing ulcers. Approximately 310 adult patients (18 years and older) will participate in this study.
Patients who require treatment for this condition will undergo a minimally invasive procedure called balloon angioplasty and stent placement. During the procedure, a physician inserts a catheter through a small puncture in the groin or leg, inflates a small balloon to open the narrowed vein, and then places a Vflower venous stent-a specially designed metal mesh tube-to keep the vein open. The Vflower stent has been approved by China's National Medical Products Administration for use in this condition.
This is an observational study, meaning your treating physician will make all treatment decisions based on your medical needs. The research team will collect data from your routine medical visits, examinations, and tests. You will be asked to return for follow-up visits at 1 month, 6 months, 12 months, and 24 months after the procedure to assess whether the vein remains open, to evaluate your symptoms, and to monitor for any complications.
The primary outcome of the study is the rate at which the treated vein remains open (patent) at 12 months after the procedure. Additional outcomes include patient-reported symptom improvement, the need for repeat procedures, and the occurrence of any complications. Participation in this study does not require any extra tests or procedures beyond those you would normally receive as part of your standard medical care. You may choose not to participate or to withdraw at any time without affecting your regular medical treatment.
This is a prospective, multicenter, real-world observational study conducted at five hospitals in China. The study aims to evaluate the effectiveness and safety of the Vflower venous stent system in adult patients with symptomatic iliofemoral vein stenosis or occlusion.
Study Design: This is an observational (non-randomized) study. Treatment decisions, including the choice of stent type and procedural technique, will be made by the treating physicians based on each patient's clinical condition. The research team will collect prospective data from routine clinical visits, imaging examinations, and laboratory tests performed as part of standard patient care.
Study Population: Approximately 310 adult patients (aged 18 years or older) with symptomatic iliofemoral vein stenosis or occlusion will be enrolled. Inclusion criteria require symptomatic disease (e.g., leg swelling, pain, varicose veins, or skin changes) and angiographic evidence of iliofemoral vein stenosis of 75% or greater, or complete occlusion. Patients with contraindications to anticoagulation, active infection, or other conditions that would preclude standard endovascular treatment will be excluded.
Procedure: Eligible patients will undergo standard endovascular intervention, which includes balloon angioplasty followed by placement of the Vflower venous stent. The Vflower stent is a self-expanding nitinol stent specifically designed for venous application, with a unique flower-shaped geometry that provides radial force while accommodating venous pulsatility and movement. The stent has been approved by the China National Medical Products Administration for use in iliofemoral venous lesions.
Follow-up and Assessments: Patients will be followed at 1 month, 6 months, 12 months, and 24 months after the procedure. At each follow-up visit, patients will undergo clinical evaluation, venous duplex ultrasonography to assess vein patency, and completion of validated patient-reported outcome questionnaires, including the Clinical, Etiology, Anatomy, and Pathophysiology (CEAP) classification and the Venous Clinical Severity Score (VCSS).
Primary Outcome: The primary outcome is the technical and clinical success rate, defined as the patency rate of the treated vein segment at 12 months post-procedure, as assessed by venous duplex ultrasonography.
Secondary Outcomes: Secondary outcomes include: (1) the change in VCSS from baseline to each follow-up visit; (2) the rate of freedom from target lesion revascularization at 12 and 24 months; (3) the incidence of device-related and procedure-related adverse events, including stent thrombosis, restenosis, stent migration, and bleeding complications; (4) health-related quality of life assessed by validated instruments; and (5) the rate of vein patency at 6, 12, and 24 months.
Data Collection: Study data will be collected using electronic case report forms (eCRFs). Data sources include medical records, imaging reports, laboratory results, and patient-reported outcomes. A centralized data management system will be used for data storage, with regular monitoring for data quality and completeness.
Statistical Analysis: Continuous variables will be summarized using means and standard deviations or medians and interquartile ranges, as appropriate. Categorical variables will be presented as frequencies and percentages. Vein patency rates will be estimated using the Kaplan-Meier method, with 95% confidence intervals. Adverse events will be coded using standardized terminology and summarized by severity and relationship to the device/procedure.
Ethical Considerations: The study protocol has been approved by the institutional review boards of all participating centers. Written informed consent will be obtained from all participants prior to enrollment. The study will be conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines.
785 studies on the registry are indexed under Venous Thrombosis; 110 are open to participants now.
This study's planned enrollment of 310 is close to the median of 301 across 274 observational studies indexed under Venous Thrombosis.
Browse Venous Thrombosis studies →Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine is the lead sponsor of 182 studies on the registry; 108 are open to participants now.
Counted across the registry records on this site, refreshed daily.
This is a single-cohort study population of approximately 310 adult patients (aged ≥18 years) with symptomatic iliofemoral vein stenosis (≥75%) or complete occlusion, with CEAP clinical classification C3-C6. The population includes patients presenting with chronic venous disease manifestations including lower limb edema, pain, heaviness, skin changes (pigmentation, eczema, lipodermatosclerosis), or active/healed venous ulcers. All enrolled patients are able to tolerate antiplatelet/anticoagulant therapy and willing to comply with all study procedures and scheduled follow-up visits at 1, 6, 12, and 24 months post-procedure.
Inclusion Criteria:
Inclusion Criteria
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
One cohort of approximately 310 adult patients (aged ≥18 years) with symptomatic iliofemoral vein stenosis (≥75%) or complete occlusion who undergo balloon angioplasty and Vflower venous stent placement.
Device: Vflower venous stent system (self-expanding nitinol stent for iliofemoral venous lesions)
Percutaneous balloon angioplasty of the iliofemoral vein prior to stent placement
12-Month Target Lesion Patency Rate
Target lesion patency at 12 months, defined as no thrombosis or occlusion, no secondary surgical/interventional intervention (excluding non-target lesions), and in-stent stenosis ≤50%, assessed by DSA, duplex ultrasonography, or CTV.
Time frame: 12 months
Device Success Rate
Successful delivery and deployment of the stent and uneventful removal of the delivery system, with no conversion to open surgery and no death within 24 hours post-procedure.
Time frame: Perioperative/Periprocedural
Procedural Success Rate
Technical success and no major adverse events before discharge.
Time frame: Perioperative/Periprocedural
Technical Success Rate
Post-procedural angiographic residual stenosis ≤50% at the target lesion. Ancillary interventions performed during the procedure are not counted as technical failure.
Time frame: Perioperative/Periprocedural
Change in CEAP Clinical Classification
Improvement of ≥1 grade in CEAP clinical classification compared to baseline, assessed at 6 months, 12 months, and 2 years post-procedure.
Time frame: Baseline, 6 months, 12 months, and 24 months
Change in Venous Clinical Severity Score (VCSS)
Improvement of ≥2 points in VCSS compared to baseline, assessed at 6 months, 12 months, and 2 years post-procedure.
Time frame: Baseline, 6 months, 12 months, and 24 months
Target Lesion Revascularization Rate
Rate of repeat endovascular treatment or revascularization for the target lesion when clinically indicated or when stenosis ≥50% at the most narrowed segment of the target lesion.
Time frame: 6 months, 12 months, and 24 months
Incidence of Major Adverse Events (MAE)
Includes device/surgery-related death, arteriovenous injury of the target vessel or target lesion requiring surgical/interventional treatment, symptomatic pulmonary embolism, device/surgery-related major bleeding requiring transfusion/surgical/interventional treatment, in-stent thrombosis, and device/surgery-related acute deep vein thrombosis.
Time frame: up to 30 days
Adverse Events
Adverse medical events occurring during follow-up, regardless of relationship to the investigational device.
Time frame: 6 months, 12 months, and 24 months
No study locations are listed for this record.
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No
Start is estimated for Oct 2026; primary completion for Feb 2027, 4 months later.
Of 103 non-industry observational studies under Venous Thrombosis, half reached primary completion within 47 months of starting (the median), counting those still running; a quarter within 21 and three quarters within 99. This study's planned 4 months is below that.
Counting every sponsor, half of 127 studies reached it within 46 months; a quarter within 21 and three quarters within 82.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine →