The primary objectives for the treatment of deep venous thrombosis (DVT) are to prevent pulmonary embolism (PE), reduce morbidity, and prevent or minimize the risk of developing the postthrombotic syndrome (PTS).
The mainstay of medical therapy has been anticoagulation since the introduction of heparin in the 1930s.  Other anticoagulation drugs have subsequently been added to the treatment armamentarium over the years, such as vitamin K antagonists and low-molecular-weight heparin (LMWH). More recently, mechanical thrombolysis has become increasingly used as endovascular therapies have increased. Absolute contraindications to anticoagulation treatment include intracranial bleeding, severe active bleeding, recent brain, eye, or spinal cord surgery, pregnancy, and malignant hypertension. Relative contraindications include recent major surgery, recent cerebrovascular accident, and severe thrombocytopenia.
The immediate symptoms of DVT often resolve with anticoagulation alone, and the rationale for intervention is often reduction of the 75% long-term risk of PTS. Systemic IV thrombolysis once improved the rate of thrombosed vein recanalization; however, it is no longer recommended because of an elevated incidence of bleeding complications, slightly increased risk of death, and insignificant improvement in PTS. The lack of a significantly reduced incidence of PTS after systemic thrombolysis (40-60%) likely reflects the inadequacy of the relatively low threshold volume of thrombus removal that was considered successful.
Thrombolytic therapy is recommended (systemic preferred over catheter directed) in hypotensive individuals with an acute PE.  Those with high-risk PE presenting in shock should undergo systemic thrombolysis; when thrombolysis is contraindicated owing to a high risk of bleeding, consider surgical thrombectomy or catheter direct thrombolysis. 
The bleeding risk of systemic thrombolysis is similar to that of catheter-directed thrombolysis, and the risk of PTS may further decrease risk. However, whether catheter-directed thrombolysis is preferred to anticoagulation has not been examined. The addition of percutaneous mechanical thrombectomy to the interventional options may facilitate decision-making, because recanalization may be achieved faster than before and with a decreased dose of lytic; therefore, the bleeding risk may be decreased.