VIRTUS: An Evaluation of the Vici™ Venous Stent System in Patients With Chronic Iliofemoral Venous Outflow Obstruction

Inclusion Criteria - Pre-Procedure Criteria: * Age ≥ 18 years * Willing and capable of complying with all follow-up evaluations at the specified times * Able and willing to provide written informed consent prior to study-specific procedures * Presence of unilateral, clinically significant, chronic non-malignant obstruction of the common femoral vein, external iliac vein, common iliac vein, or any combination thereof, defined as a ≥50% reduction in target vessel lumen diameter (to be measured by venogram during procedure) * Clinically significant venous obstruction defined as meeting at least one of the following clinical indicators: * Clinical severity class of CEAP classification ≥3 * VCSS Pain Score ≥2 * Negative pregnancy test in females of child-bearing potential * Intention to stent the target lesion only with the Veniti Vici Venous Stent Exclusion Criteria - Pre-Procedure Criteria: * Presence or history of clinically significant pulmonary emboli within 6 months prior to enrollment. * Venous obstruction that extends into the inferior vena cava (IVC) * Contralateral disease of the common femoral vein, external iliac vein, common iliac vein, or any combination thereof with planned treatment within 30 days after subject enrollment * Life expectancy \<12 months * Female of childbearing potential who is pregnant or plans to become pregnant during the duration of the clinical study * Uncontrolled or active coagulopathy OR known, uncorrectable bleeding diathesis with the following definitions: * Uncorrected INR ≥2.0 or aPTT ≥1.5 X normal local lab value * Platelet count \<80,000 * Uncorrected hemoglobin of ≤ 9 g/dL * Patients with an estimated glomerular filtration rate (eGFR) \<30 mL/min. In patients with diabetes mellitus, eGFR \<45 mL/min. * Known hypersensitivity to nickel or titanium * Contrast agent allergy that cannot be managed adequately with pre-medication * Intended concurrent thrombolysis or thrombectomy procedure OR intended or planned (within 30 days) adjuvant procedure such as creation of temporary arteriovenous fistula, placement of IVC filter, endovenectomy or saphenous vein ablation * Current or recent (within 30 days) active participation in another drug or device clinical trial (Participation in observational studies is acceptable.) * Patient judged to be a poor candidate by the primary investigator * Patients who have had any prior surgical or endovascular intervention of the target vessel \[Note: Patients who have had catheter-directed or mechanical thrombolysis in the target vessel for DVT at least 3 month (90 days) prior to the VIRTUS index procedure may be included in the trial.\] Exclusion Criteria - Intra-Procedural Criteria: * Patients in whom the lesions cannot be traversed with a guide wire. * Patients where the obstruction extends into the inferior vena cava or below the level of the lesser trochanter. * Patients whose vein diameters are not within limits stated in current Instructions for Use as determined by venogram. * Patients who do not meet the venogram binary stenosis definition, as determined by the treating physician.