An interventional study of Stents in Deep Vein Thrombosis, Venous Stasis and Venous Insufficiency, sponsored by Washington University School of Medicine. Active, not recruiting at 29 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-01-28.
Sponsored by Washington University School of Medicine · Not applicable, Interventional, and Treatment
The purpose of this study is to determine if the use of image-guided, endovascular therapy (EVT) is an effective strategy with which to reduce Post Thrombotic Syndrome (PTS) disease severity and improve quality of life in patients with established disabling iliac-obstructive post thrombotic syndrome (DIO-PTS).
The rationale for performing the C-TRACT Trial is based upon:
We will determine if EVT should be routinely used to treat DIO-PTS. If so, this finding will fundamentally change DIO-PTS practice towards more frequent use of EVT. If EVT proves ineffective or unsafe, this finding will reduce or eliminate the use of potentially risky and expensive procedures.
250 subjects with established DIO-PTS will be randomized in a 1:1 ratio to either EVT or No-EVT treatment groups. All participants will receive standard PTS therapy. Subjects will be enrolled over approximately 36 months in 20-40 U.S. Participants enrolled in C-TRACT protocol versions prior to 5.0 will be followed for 24 months. Subjects enrolled on protocol version 5.0 or after will be followed for 6 months. The study will take approximately 6 years to complete.
785 studies on the registry are indexed under Venous Thrombosis; 110 are open to participants now.
This study's enrollment of 225 is above the median of 152 across 477 interventional studies indexed under Venous Thrombosis.
Browse Venous Thrombosis studies →Washington University School of Medicine is the lead sponsor of 1,803 studies on the registry; 271 are open to participants now.
Of its 329 completed or terminated interventional studies of FDA-regulated products, 216 (66%) have results posted.
Counted across the registry records on this site, refreshed daily.
Inclusion Criteria: Subjects must meet BOTH of these Criteria
Ipsilateral iliac vein obstruction documented within 12 months prior to consent by either:
Exclusion Criteria: Subjects meeting any of these criteria will be excluded.
Note - patients who initially meet an exclusion criterion can have eligibility re-evaluated on a subsequent occasion.
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.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
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.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Subjects randomized to EVT will receive the following: 1. imaging-guided iliac vein stent placement; 2. anticoagulant therapy for at least 6 months; 3. oral aspirin 81 mg for at least 6 months; and 4. optimal PTS therapy: medical, compression, lifestyle measures, and venous ulcer care
Device: Stents
Optimal PTS therapy: medical, compression, lifestyle measures, and venous ulcer care
US-guided puncture of vein, fluoroscopic monitoring of catheter/guidewire manipulations, baseline venogram and intravascular ultrasound of CFV through infrarenal IVC. Iliac vein should be pre-dilated to at least 12 mm. Bare, self-expanding stents made of elgiloy or nitinol legally marketed in the US for any indication and that are at least 12 mm in diameter should be used to recanalize the entire diseased segment of vein. The use of devices \> 14 mm is highly recommended for the iliac vein and should be dilated to at least 14 mm, unless compelling patient factors dictate dilatation to a smaller diameter. Balloon angioplasty of inflow veins if needed to optimize inflow, per standard practice.
PTS Severity
"Venous Clinical Severity Scale (VCSS) score, adjusted for baseline"
Time frame: over 6 months follow-up
Venous quality of life
VEINES-QOL questionnaire
Time frame: 6 months
Gereric quality of life
Short-Form-36 survey, physical component score
Time frame: 6 months
Estimated calf volume
Measure calf length/diameter, formula for truncated cone
Time frame: 6 months
Presence of open ulcer
Blinded clinic assessment
Time frame: 6 months
PTS severity (secondary)
Villalta PTS Scale score
Time frame: 6 months
Major bleeding
Overt, requiring \> 2 units pRBC or critical location
Time frame: 6 months
Recurrent venous thrombeombolism
Objectively confirmed proximal DVT or PE
Time frame: 6 months
Death
All-cause mortality
Time frame: 6 months
Valvular reflux
Venous Segmental Disease Scale, reflux score
Time frame: 6 months
Venous obstruction
Venous Segmental Disease Scale, obstruction score
Time frame: 6 months
Venous quality of life
VEINES-QOL questionnaire
Time frame: 12 months
Gereric quality of life
Short-Form-36 survey, physical component score
Time frame: 12 months
PTS severity (remote)
Patient-Reported Villalta
Time frame: 12 months
Venous quality of life
VEINES-QOL questionnaire
Time frame: 18 months
Gereric quality of life
Short-Form-36 survey, physical component score
Time frame: 18 months
PTS severity (remote)
Patient-Reported Villalta
Time frame: 18 months
Venous quality of life
VEINES-QOL questionnaire
Time frame: 24 months
Gereric quality of life
Short-Form-36 survey, physical component score
Time frame: 24 months
PTS severity (remote)
Patient-Reported Villalta
Time frame: 24 months
Major bleeding
Overt, requiring \> 2 units pRBC or critical location
Time frame: 24 months
Recurrent venous thrombeombolism
Objectively confirmed proximal DVT or PE
Time frame: 24 months
Death Death
All-cause mortality
Time frame: 24 months
Plan to share: Yes
Supporting information: Study protocol, Informed consent form
This study is active, not recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.
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