• 1 - A condition where surgery has been performed (Surgical code)
• 2 - A condition where no surgery has been performed (non-surgical code)
  • 2 - Cardiovascular
    • 11 - Great veins
      • 30 - Obstruction
        • 1 - Superior vena caval obstruction or thrombosis
        • 2 - Inferior vena caval obstruction or thrombosis