**Perivenous Dexamethasone Therapy Study** This study explores how an anti-inflammatory medication called *dexamethasone* can help people with deep vein thrombosis (DVT). DVT is when a blood clot forms in deep veins, often in the legs, causing pain and swelling. The research uses a special tool called the Bullfrog® Micro-Infusion Device to deliver dexamethasone around veins after a blood clot has been cleared. The goal is to see if this can stop new clots from forming and improve symptoms for up to 24 months. **Key Points:** - **Duration & Visits**: Participants will be involved in the study and will have follow-up visits for up to 24 months. - **Eligibility**: Adults aged 18 to 89, not currently in another drug study, and able to take medication. - **Treatment & Risks**: Involves using anti-clotting drugs post-procedure; some people might be allergic to the drugs used. Participants must be willing to follow the study procedures and attend all scheduled visits.