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. conditions: Postthrombotic Syndrome studyType: INTERVENTIONAL phases: NA allocation: NA interventionModel: SINGLE_GROUP primaryPurpose: PREVENTION masking: NONE count: 400 type: ESTIMATED name: Quantification of deep vein thrombosis burden and assessment of post-thrombotic syndrome measure: Presence of moderate to severe Post-thrombotic Syndrome (PTS) measure: Thrombosis burden measure: Presence of moderate to severe PTS adjusted to other prognostic factors at baseline measure: Thrombosis burden adjusted to other prognostic factors at baseline measure: Presence of moderate to severe PTS adjusted to other prognostic factors at baseline and during follow-up measure: Thrombosis burden adjusted to other prognostic factors at baseline and during follow-up measure: Time to complete resolution of the thrombus as a function of thrombosis burden at baseline measure: Presence of moderate to severe PTS at baseline and at follow-up visits measure: Thrombosis burden at baseline and at follow-up visits measure: Disease specific health related quality of life measure: General health related quality of life measure: Coagulation and fibrinolysis markers measure: Fibrinolytic and pro-coagulant activities of microvesicles/microparticles sex: ALL minimumAge: 18 Years stdAges: ADULT stdAges: OLDER_ADULT facility: Centre Hospitalier de Carcassonne city: Carcassonne state: Aude zip: 11010 country: France name: Géraldine PAOLI-CAZANAVE role: CONTACT email: geraldine.paoli-cazanave@ch-carcassonne.fr lat: 43.21667 lon: 2.35 facility: Cabinet libéral city: Martigues state: Bouches-du-Rhône zip: 13500 country: France name: Damien DIAS role: CONTACT email: dam.dias@free.fr lat: 43.40735 lon: 5.05526 facility: Cabinet libéral city: Ajaccio state: Corse-du-sud zip: 20090 country: France name: Jean-François SECONDI role: CONTACT email: dr.jf.secondi@gmail.com lat: 41.91888 lon: 8.73811 facility: Cabinet libéral city: Ajaccio state: Corse-du-sud zip: 20090 country: France name: Céline DE MARI role: CONTACT email: dr.celine.demari@gmail.com lat: 41.91888 lon: 8.73811 facility: Centre Hospitalier Universitaire de Brest city: Brest state: Finistère zip: 29069 country: France name: Benjamin ESPINASSE role: CONTACT email: Benjamin.espinasse@chu-brest.fr lat: 48.3903 lon: -4.48628 facility: Clinique Rive Gauche city: Toulouse state: Haut-Garonne zip: 31076 country: France lat: 43.60426 lon: 1.44367 facility: Hospices Civils de Lyon, Hôpital Edouard Herriot city: Lyon state: Rhône zip: 69003 country: France name: Judith CATELLA role: CONTACT email: judith.catella@chu-lyon.fr lat: 45.74848 lon: 4.84669 facility: Centre Hospitalier Universitaire Amiens Picardie city: Amiens state: Somme zip: 830054 country: France name: Simon SOUDET role: CONTACT email: Soudet.simon@chu-amiens.fr lat: 49.9 lon: 2.3 facility: Centre Hospitalier de Fréjus/Saint-Raphaël city: Fréjus state: Var zip: 83600 country: France name: Hatem BOUGHIDA role: CONTACT email: hatemboughida@yahoo.fr lat: 43.43286 lon: 6.73524 facility: Polyclinique Les Fleurs city: Ollioules state: Var zip: 83190 country: France name: Anaïs CORNE role: CONTACT email: anaiscorne@gmail.com lat: 43.13517 lon: 5.848 facility: Centre cardio-vasculaire Esterel city: Saint-Raphaël state: Var zip: 83700 country: France lat: 43.42332 lon: 6.7735 facility: Cabinet libéral city: Sanary-sur-Mer state: Var zip: 83110 country: France name: Colin RICHARD role: CONTACT email: colin.richard29@gmail.com lat: 43.11783 lon: 5.80007 facility: Cabinet libéral city: Six-Fours-les-Plages state: Var zip: 83140 country: France name: Sophia BENSEDRINE role: CONTACT email: sophia.ange@wanadoo.fr lat: 43.1 lon: 5.85 facility: Centre Hospitalier Intercommunal Toulon La Seyne-sur-Mer city: Toulon state: Var zip: 830054 country: France name: Jean-Noël POGGI role: CONTACT email: jeannoel.poggi@ch-toulon.fr lat: 43.12442 lon: 5.92836 facility: Centre Hospitalier d'Avignon city: Avignon state: Vaucluse zip: 84000 country: France name: Olivier GRAS role: CONTACT email: GRAS.Olivier@ch-avignon.fr lat: 43.94834 lon: 4.80892 hasResults: False