Anticoagulant Plus Antiplatelet Therapy Following Iliac Vein Stenting

Inclusion Criteria: IC1. Subjects who were diagnosed with deep venous thrombus (DVT) with ipsilateral iliac venous stenosis (\>50%). The ipsilateral iliac venous stenosis can be caused either by iliac vein compression (i.e. Cockett syndrome) or residue iliac venous thrombus after percutaneous mechanic thrombectomy. IC2. Subjects who accepted percutaneous mechanic thrombectomy (PMT) to decrease the burden of thrombus, with or without catheter directed thrombolysis (CDT). IC3. Subjects who accepted iliac venous stent(s) implantation during the perioperative period of PMT or CDT (≤30 days post PMT or CDT) . Exclusion Criteria: EC1. Subject has chronic DVT or the onset of DVT is longer than 3 weeks, or chronic DVT. EC2. Subject has isolated distal DVT, which does not affect ipsilateral femoral or iliac vein. EC3. Subject has glomerular filtration rate \< 60ml/min. EC4. Subject has ipsilateral varicose vein or suffers from ipsilateral venous insufficiency prior to the DVT. The manifestations of venous insufficiency include skin pigmentation, edema, lipodermatosclerosis and venous ulcer. EC5. Subject has acute arterial embolism on either side or suffers from known moderate or greater stenosis at abdominal aorta, ipsilateral iliac artery and ipsilateral lower extremity artery. EC6. Subject has known aneurysm(s) or current limiting dissection at abdominal aorta, ipsilateral iliac artery and ipsilateral lower extremity artery. EC7. Subject has contraindication to antiplatelet drugs or anticoagulants. EC8. Subject has systemic disease(s) that cannot be treated by current medicine. EC9. Subject has been taking anticoagulants or antiplatelet drugs for other diseases prior to the DVT. EC10. Subject less than 18 years old or rejected to join this study. EC11. Subject has myocardial infarction during the past 6 months. EC12. EC12. Subject who is at high bleeding risk\*. \* Subject who has at least one of the below conditions will be considered at high bleeding risk: Primary history of intracerebral haemorrhage or ischemic stroke, history of other intracranial pathology, recent gastrointestinal bleeding or anaemia due to possible gastrointestinal blood loss, other gastrointestinal pathology associated with increased bleeding risk, liver failure, bleeding diathesis or coagulopathy, extreme old age or frailty, or renal failure requiring dialysis or with eGFR \<15ml/min/1.73 m2.