The figure illustrates a proposed classification system describing six levels of proximal great saphenous vein thrombus following superficial venous ablation therapies for the purpose of guiding clinical therapy and further research.
Superficial vein thrombosis:
Level I: Thrombus below the superficial epigastric vein
Level II: Thrombus up to the origin of the superficial epigastric vein
Level III: Thrombus up to but not into the common femoral vein
Level IV: Thrombus bulging into the common femoral vein but not adherent to the wall of the common femoral vein
Deep vein thrombosis:
Level V: Thrombus extending into the common femoral vein and adherent to the adjacent wall
Level VI: Occlusive thrombus of the common femoral vein
EHIT: endovenous heat-induced thrombus.
Modified from: Lawrence PF, Chandra A, Wu M, et al. Classification of proximal endovenous closure levels and treatment algorithm. J Vasc Surg 2010; 52:388.