Lawrence classification of venous ablation level

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