CLINICAL TRIAL / NCT03250247

Inclusion Criteria: Subjects must meet BOTH of these Criteria 1. Disabling (moderate-to-severe) PTS, defined by a) presence of chronic venous disease > or = 3 months duration in a leg with history of DVT, as determined by the site principal investigator or a physician co-investigator; and b) substantial limitation of daily activities or work capacity due to venous symptoms or an open venous ulcer, per the same investigator. 2. Ipsilateral iliac vein obstruction documented within 12 months prior to screening by either: 1. Occlusion or >50% or = 50% stenosis of the iliac vein on venogram, CT venogram, MR venogram, or intravascular ultrasound (IVUS) or 2. Air plethysmography showing deep venous obstruction of the ipsilateral leg (reduced venous outflow fraction), and ultrasound showing echogenic material in the ipsilateral iliac vein and non-phasic continuous Doppler flow in the ipsilateral common femoral vein (CFV) in the presence of normal phasic Doppler flow in the contralateral CFV. Exclusion Criteria: Subjects meeting any of these criteria will be excluded. 1. Age less than 18 years 2. Acute ipsilateral proximal DVT episode within the last 3 months, or acute contralateral DVT for which thrombolytic therapy is planned 3. Lack of suitable inflow into the ipsilateral common femoral vein per the treating physician 4. Previous stent placement in the infrarenal IVC or ipsilateral iliac or common femoral vein 5. Absence of PTS of at least moderate severity 6. Chronic arterial limb ischemia (ankle-brachial index < 0.5 within the previous 1 month) in the ipsilateral leg (if peripheral arterial disease is present or suspected, an ankle-brachial index should be obtained and documented) 7. Presence of open venous ulcer > 50 cm2 area, suspicion for active ulcer infection, or visualization of bone or tendon within the ulcer in the ipsilateral leg 8. Inability to tolerate endovascular procedure due to acute illness, or general health 9. Severe allergy to iodinated contrast refractory to steroid premedication 10. Known allergy to stent or catheter components 11. Hemoglobin < 8.0 g/dl, uncorrectable INR > 3.05, or platelet count < 75,000/ml 12. Severe renal impairment (on chronic dialysis or estimated GFR < 30 ml/min) 13. Disseminated intravascular coagulation or other major bleeding diathesis 14. Pregnancy (positive pregnancy test) 15. Life-expectancy < 6 months or chronically non-ambulatory for reasons other than PTS 16. Inability to provide informed consent or to comply with study assessments Note - patients who initially meet an exclusion criterion can have eligibility re-evaluated on a subsequent occasion.