Perivenous Dexamethasone Therapy: Examining Reduction of Inflammation After Thrombus Removal to Yield Benefit in Acute Femoropopliteal DVT

Inclusion Criteria:

1. Provision of signed and dated informed consent form prior to receiving anynon-standard of care, protocol-specific procedures.

2. Stated willingness to comply with all study procedures including completion ofquestionnaires and follow-up visits and availability for the duration of the study.

3. Male or female, aged 18 to 89 years.

4. For females of reproductive potential: use of highly effective contraception (abstinence is acceptable) for at least 1 month prior to study treatment (unlessthey had given birth within the 1 month prior to study treatment), and agreement touse such a method for at least 30 days after study treatment.

5. Onset of acute DVT symptoms of 14 days or less prior to initial intervention in thestudy limb.

6. Ability to take oral medication and be willing to adhere to the prescribedanti-coagulant regimen.

7. Post-procedural prescription for at least 28 days low molecular weight heparinfollowed by therapeutic anticoagulant of investigator's choice for 12 months minimumas part of post-interventional medication regimen.

8. Minimum of 28 days of prescribed antiplatelet agent (aspirin or P2Y12 inhibitor) forpatients receiving stents.

9. DVT located in any of the major femoropopliteal veins (common femoral, femoral,and/or popliteal above the tibial plateau), with possible extension downstream intothe iliac veins.

10. Successful recanalization of the target vein with removal of acute thrombus.

Exclusion Criteria:

1. Current enrollment in another non-registry clinical study of systemic drug therapyor another device study that has not completed its primary endpoint, including priorenrollment in this study. Concurrent enrollment in registry studies of approveddevices or drugs are acceptable.

2. Lack of capability of understanding the nature, significance and implications of theclinical trial.

3. Body Mass Index between 40 kg/m2 and 45 kg/m2, with significant comorbidity which,in the Investigator's discretion, could impair follow-up or study outcomes.

4. Body Mass Index > 45 kg/m2.

5. Non-ambulatory status prior to DVT occurrence.

6. In the study leg: current established PTS (Villalta ≥ 5 for more than 14 days),current known symptomatic deep venous insufficiency for more than 14 days, orprevious symptomatic DVT within the last 365 days.

7. In the contralateral (non-study) leg: symptomatic DVT that, in the opinion of theoperating physician, will require a subsequent open or endovascular surgery in thefollowing 30 days.

8. In cases with symptoms of limb-threatening circulatory compromise, ankle-brachialindex <0.4, absolute ankle pressure <50 mmHg or absolute toe pressure <30 mmHg.

9. Pulmonary embolism (PE) defined as either massive (systolic blood pressure < 90 mmHgand/or patient on IV vasoactive medication to support blood pressure), orintermediate high-risk PE, as defined by the European Society Guideline onmanagement of PE. Low-risk PE and/or intermediate low-risk PE can be enrolled.

10. Inability to tolerate contemporary venous intervention procedure due to severedyspnea or acute systemic illness.

11. Allergy or hypersensitivity to any drugs planned for use in the case (includingdexamethasone sodium phosphate, iodinated contrast, low molecular-weight heparin, orrecombinant tissue plasminogen activator, rtPA, if planned), except formild-moderate contrast allergies for which steroid pre-medication can be used.

12. History of, or active heparin-induced thrombocytopenia (HIT).

13. Hemoglobin < 8.0 g/dl.

14. INR > 1.6 before starting anticoagulation.

15. Platelets < 100,000/ml.

16. Severe renal impairment (estimated glomerular filtration rate < 30 ml/min).

17. Active bleeding, recent (< 1 mo) GI bleeding, severe liver dysfunction, bleedingdiathesis.

18. Recent (< 3 mo) internal eye surgery or hemorrhagic retinopathy.

19. Recent (< 10 days) major surgery, trauma, cardiopulmonary resuscitation, or otherinvasive procedure which, in the Investigator's discretion, could impair follow-upor study outcomes.

20. Obstetrical delivery <72 hours prior to procedure.

21. Hemorrhagic stroke within the last 365 days.

22. Intracranial/intraspinal bleed within the last 365 days.

23. Intracranial/intraspinal tumor within the last 365 days.

24. Intracranial/intraspinal vascular malformation within the last 365 days.

25. Intracranial/intraspinal aneurysm within the last 365 days.

26. Active symptomatic COVID-19 infection that, in the Investigator's discretion, couldimpair follow-up or study outcomes.

27. Severe hypertension on repeated readings (systolic blood pressure > 180 mmHg ordiastolic blood pressure > 105 mmHg). This can be treated, and blood pressure mustbe stable before venous access is obtained (systolic blood pressure <140 mmHg).

28. Pregnant or breastfeeding.

29. Life expectancy < 2 years (e.g. due to active cancer).

30. Major thrombus of the inferior vena cava (IVC) (occlusive or near-occlusive)extending at least one centimeter above the common iliac confluence.

31. Inability to obtain venous access.

32. Inability to recanalize the target vein segment with less than 30% residualobstruction due to thrombus.

33. History of ipsilateral venous stent.

34. DVT target length intended for drug treatment exceeds 50 cm.