DEFIANCE: RCT of ClotTriever System Versus Anticoagulation In Deep Vein Thrombosis

Inclusion Criteria * Age ≥ 18 years * Proximal lower extremity unilateral DVT involving at least the common femoral, external iliac, or common iliac veins, alone or in combination * Symptom onset within 12 weeks of enrollment in the study * Significant symptoms, as defined by a Villalta score \> 9 * Willing and able to provide informed consent Exclusion Criteria * Bilateral iliofemoral DVT * Prior venous stent in the target venous segment * IVC aplasia/hypoplasia or other congenital anatomic anomalies of the IVC or iliac veins * IVC filter in place at the time of enrollment * Limb-threatening circulatory compromise (e.g., phlegmasia) * Clot in transit including IVC thrombus presenting as extension of \>2cm into the IVC from the CIV * Symptomatic PE with right heart strain where the physician judges that a DVT intervention is inappropriate at this time. * Inability to be a candidate for intervention due to medical or technical reasons based on physician judgement * Severe allergy, hypersensitivity to, or thrombocytopenia from heparin * Severe allergy to iodinated contrast agents that cannot be mitigated * Hemoglobin \< 8.0 g/dL, INR \> 1.7 before warfarin was started, or platelets \< 50,000/µl which cannot be corrected prior to enrollment * Severe renal impairment (estimated GFR \< 30 ml/min) in patients who are not yet on dialysis * Inability to provide therapeutic anticoagulation per Investigator discretion * Uncontrolled severe hypertension on repeated readings (systolic \> 180mmHg or diastolic \> 105mmHg) * Recently (\< 30 days) had DVT interventional procedure * Subject is participating in another study that may interfere with this study * Life expectancy \< 6 months or chronic non-ambulatory status * Known hypercoagulable states that, in the opinion of the Investigator, cannot be medically managed throughout the study period * Subject has any condition for which, in the opinion of the Investigator, participation would not be in the best interest of the subject (e.g., contraindication to use of ClotTriever per local approved labeling, compromise the well-being or that could prevent, limit, or confound the protocol-specified assessments) * Subject has previously completed or withdrawn from this study * Patient unwilling or unable to conduct the follow up visits per protocol