Thrombus Elastography in Venous Thrombo-Embolism.

Study Overview
=================
Brief Summary
-----------------
Venous Thrombo-Embolic Disease (VTED) is a serious and common ailment, defined by the growth of a clot - or thrombus - in a vein, and/or as the migration of this thrombus to a pulmonary artery. It represents the third cause of death after cardio-vascular disease and cancer, and encompass superficial, muscular and Deep Venous Thrombosis (DVT), and Pulmonary Embolisms (PE), which can be isolated or associated. Ultrasound is today the most frequently used exam to diagnose DVT. However, it's unable to provide information on thrombus age or cause. Elastography is an imaging technic which aims to analyse elastic properties of a tissue, by applying a mechanical impulse on it, and could be an interesting tool in thrombus exploration, and provide additional information.

Detailed Description
-----------------
Proximal deep venous thrombosis of a lower limb was defined as any venous thrombosis involving the ilio-femoral and/or femoro-popliteal axes, with or without cava thrombosis or distal DVT. A DVT was assumed provoked, as recommended by AFSSAPS (2009) and ACCP (2012), when there was a major transient risk factor (surgery, prolonged immobilization ≥3 days, lower limb fracture) in the last three months, or a persistent risk factor (Antiphospholipid syndrome, active cancer). In case of absence of at least one of these factors, DVT was considered unprovoked. A DVT was supposed recent when there was no known DVT in the patient medical history. The association with a Pulmonary Embolism was assessed by the presence of PE diagnosis in the medical report. It had to be diagnosed following the ESC guidelines, with a thoracic CT scan and/or a V/Q lung scan. In this study, we analysed the shear wave's velocity (expressed in m/s). Acquisitions were obtained during the venous ultrasound realised for the diagnosis of DVT. All measures were made on the same ultrasonic device, with the ShearWave module.

Official Title
-----------------
Assessment of Thrombus Stiffness Using Ultrasound Elastography in Venous Thrombo-embolism.

Conditions
-----------------
Venous Thromboembolism

Intervention / Treatment
-----------------
* Diagnostic Test: Ultrasound Elastography


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Over 18 years old. Suffering from a proximal DVT (DVT) of at least one lower limb. Thrombosis is assumed to be recent (no history of ipsilateral DVT). Non opposition obtained. Exclusion Criteria: Patient suffering from an inferior vena cava thrombosis with no extension to ilio-femoral veins. Physical or cognitive inability to consent. Patient refusal.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: Ultrasound Elastography|Ultrasound elastography aims to assess the stiffness of a tissue, submitting it to an ultrasound impulse.|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Shear Wave Speed within the thrombus. | Quantitative data, in meter per second. | At VTE diagnostic (Day 0) | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Elasticity Imaging Techniques, Venous Thromboembolism