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Clot size in leg vein thrombosis and later post-thrombotic syndrome

Studies whether clot size on ultrasound predicts post-thrombotic syndrome after a first leg clot.

Key facts

Who runs it
Centre Hospitalier Intercommunal de Toulon La Seyne sur Mer
Where
France26 sites in 1 countryChoose a country to see its sites
Trial code
Registry title
DVT Burden and the Risk of Post-thrombotic Syndrome
Status
Recruiting
People taking part
400 people, planned
Started
5 Jun 2024
Expected to end
Jun 2027
Type of study
Interventional
Treatments tested
  • Quantification of deep vein thrombosis burden and assessment of post-thrombotic syndrome
Record updated
7 July 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with a first, sudden blood clot in a deep leg vein that causes symptoms. It studies whether the clot size predicts later leg problems (post-thrombotic syndrome).

Age
18 years and older
Sex
All sexes
Disease stage
Acute deep vein thrombosis of the legs with symptoms, confirmed by ultrasound. People with a stable lung clot linked to the leg clot can join.
Earlier treatment
Cannot join after more than 5 days of blood thinner treatment (preventive or full dose). Blood thinner treatment must be planned for at least 3 months.

Main reasons for not taking part

  • Pregnant, in labour or breastfeeding
  • Unstable lung clot (systolic blood pressure < 90 mmHg, shock or cardiac arrest)
  • Earlier blood clot in either leg, or symptoms in both legs
  • Leg fracture or leg bone surgery in the last 3 months
  • High bleeding risk, or life expectancy < 6 months

The registry criteria, word for word

Show all 18 criteriaShow less

Who can take part

  • Age ≥ 18 years
  • Patients with symptomatic acute deep venous thrombosis of the lower limbs confirmed by ultrasound on the criteria of venous incompressibility and direct image of the thrombus (patients with stable pulmonary embolism associated with a symptomatic deep venous thrombosis can be included)
  • Affiliates or beneficiaries of a social security scheme

Who cannot take part

  • Fracture or orthopedic surgery of the lower limbs in the last 3 months
  • Indication for interruption of the inferior vena cava or venous recanalisation (endovascular, thrombolysis or surgery)
  • Pulmonary embolism haemodynamically unstable defined by systolic blood pressure < 90 mmHg or a drop in systolic blood pressure of at least 40 mmHg during at least 15 min, shock or cardiac arrest
  • Asymptomatic venous thrombosis
  • Symptomatic venous thrombosis of both lower limbs (patients with bilateral deep venous thrombosis but symptomatic on one side only can be included)
  • History of ipsilateral or contralateral venous thrombosis of the lower limb
  • Patients taking part in a research project for venous thromboembolism that can interfere with the conduct of DVT-BURDEN research
  • Patient estimated at high risk of bleeding according to investigator clinical judgment (renal, platelet, digestive, hepatic, neurological... origin)
  • Dependance caused by age or secondary to a chronic affection, going from the inability to stand up or walk alone without help to bed or armchair rest over
  • Pregnant women, women in labour or breastfeeding mothers
  • Prophylactic or therapeutic anticoagulant treatment > 5 days
  • Expected duration of anticoagulant treatment < 3 months (all patients must have a minimum treatment of 3 months)
  • Refusal or inability to give written informed consent to participate in the study
  • Life expectancy < 6 months
  • Patients under legal protection (guardianship, curatorship, etc.) or safeguard of justice

This trial has no sites in United States.

It has sites in one country. Choose a country to see its sites.

About the trial

What the trial wants to find out

Post-thrombotic syndrome (PTS) is the most common chronic complication of deep vein thrombosis (DVT), with major consequences for patient quality of life and cost of management. Identifying patients at high risk of developing PTS could be useful for its prevention and may lead to more appropriate therapeutic strategies to reduce its incidence and severity.

Read full original descriptionShow less

Prognostic tools for predicting risk are very useful for choosing the optimum treatment and improving patient management and are a preliminary step before developing predictive models useful for determining sensitivity to treatment. At present, although several prognostic markers and models have been proposed, it is still difficult to predict who will develop a PTS or a moderate to severe PTS. The development of PTS is multifactorial and depends largely on the extent and severity of venous obstruction which supports the theory of thrombosis burden (DVT-Burden) as a potential prognostic marker for PTS. It therefore seems important to study the association between thrombosis burden and the occurrence of PTS.

The Venous Volumetric Index or VVI (Ouriel 1999) will be used for quantifying DVT-Burden. The VVI was constructed by calculating the volume from the diameter and length of 14 venous segments from the calf veins to the inferior vena cava. The VVI has been validated for its ability to discriminate between symptomatic and asymptomatic DVT and has shown superior performance to other methods for quantifying DVT.

This study aim to assess the performance of baseline DVT-burden estimated by the VVI score on ultrasound for predicting the occurrence and the severity of PTS as assessed by the Villalta scale at 6 months.

The group in the trial

  • Association between thrombosis burden and occurrence of PTSTreatment being tested

    Treatment: Quantification of deep vein thrombosis burden and assessment of post-thrombotic syndrome

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

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Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
Baseline Ultrasound Venous Thrombosis Burden and the Risk of Post-thrombotic Syndrome in Patients With a First Acute Episode of Symptomatic Deep Vein Thrombosis of the Lower Limbs - The "DVT-Burden" Project -
Plain-language title
Clot size in leg vein thrombosis and later post-thrombotic syndromeGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 15 November 2026.
Record updated
7 July 2026