Rivaroxaban Anticoagulation for Superficial Vein Thrombosis

Inclusion Criteria: \- Symptomatic Superficial Vein Thrombosis of the leg of ≥5 cm length (diagnosed clinically or with ultrasound) Exclusion Criteria: * Age \<18 years * Symptoms \>42 days * Receiving an anticoagulant for another indication (example: atrial fibrillation) when Superficial Vein Thrombosis started. * Superficial Vein Thrombosis already treated with more than 3 days of anticoagulation (example. fondaparinux or Low Molecular Weight Heparin). * Planned treatment of Superficial Vein Thrombosis with a course of anticoagulant therapy. * Another indication for anticoagulant therapy (example. Deep Vein Thrombosis, Pulmonary Embolism, atrial fibrillation). * Judged to require immediate ligation of the saphenofemoral junction or stripping of thrombosed varicose veins. * proximal Deep Vein Thrombosis or Pulmonary Embolism within the past 12 months. * Superficial Vein Thrombosis associated with sclerotherapy or an intravenous canula. * A high risk of bleeding as evidenced by any of the following: 1. Active bleeding 2. Bleeding within the past 30 days due to a cause that has not fully resolved. 3. Known or expected thrombocytopenia with a platelet count of less than 80,000 x 10 9/L. 4. History of ever having had spontaneous intracranial bleeding, or any intracranial bleeding within the past 3 months. 5. Receiving dual antiplatelet therapy (example. aspirin and clopidogrel). * Elevated creatinine level is suspected and creatinine clearance has not been estimated, OR creatinine clearance (Cockcroft-Gault equation) of less than 30 ml/min. * Clinically relevant hepatic disease (including Child-Pugh B and C) is known or suspected (example., associated with: International Normalized Ratio \>1.7; total bilirubin \>2 upper limit of normal; or Alanine aminotransferase (ALT) or Aspartate aminotransferase (AST) \>3 times upper limit of normal). * Ongoing requirement for systemic treatment with azole-antimycotics (except fluconazole), Human Immunodeficiency Virus (HIV) -protease inhibitors, or strong Cytochrome P450 3A4 (CYP3A4) inducers due to the potential interaction with rivaroxaban. * Pregnant or lactating women, or at risk of becoming pregnant. * Life expectancy less than 90 days * Patient is unwilling or unable to comply with the protocol (example. unable to attend follow-up visits because of geographic inaccessibility). * Participating in a competing clinical investigation and receiving any other investigational agent(s).