The standard treatment of DVT is anticoagulants (blood thinners). Following treatment of a clot in the deep veins with anticoagulants, the clot may resolve or, it may turn into scar tissue inside the vein. The scar tissue in the vein can cause either damage to the valves leading to backward flow or a blockage in the vein resulting in poor return of blood to the heart. The blockage in the veins is called chronic venous stasis.

While DVT and vein damage can occur in any of the deep veins in the leg, the more proximal larger (iliac) veins in the pelvis tend to respond poorly to anti coagulation alone.

The abnormal flow that occurs because of the underlying blockage may result in symptoms of chronic venous disease. Symptoms include heavy legs, swelling of the legs or skin discoloration and/or ulcer formation.