AAST liver injury scale

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The AAST (American Association for the Surgery of Trauma) liver injury scale, most recently revised in 2018, is the most widely used liver injury grading system .

The 2018 update incorporates "vascular injury" (i.e. pseudoaneurysm, arteriovenous fistula) into the imaging criteria for visceral injury .

Classification

  • grade I
    • hematoma: subcapsular, <10% surface area
    • laceration: capsular tear, <1 cm  parenchymal depth
  • grade II
    • hematoma: subcapsular, 10-50% surface area
    • hematoma: intraparenchymal <10 cm diameter
    • laceration: capsular tear 1-3 cm parenchymal depth, <10 cm length
  • grade III
    • hematoma: subcapsular, >50% surface area of ruptured subcapsular or parenchymal hematoma
    • hematoma: intraparenchymal >10 cm
    • laceration: capsular tear >3 cm parenchymal depth
    • vascular injury with active bleeding contained within liver parenchyma
  • grade IV
    • laceration: parenchymal disruption involving 25-75% hepatic lobe or involves 1-3 Couinaud segments 
    • vascular injury with active bleeding breaching the liver parenchyma into the peritoneum
  • grade V
    • laceration: parenchymal disruption involving >75% of hepatic lobe
    • vascular: juxtahepatic venous injuries (retrohepatic vena cava / central major hepatic veins)

Additional points

  • advance one grade for multiple injuries up to grade III
  • "vascular injury" (i.e. pseudoaneurysm or AV fistula) - appears as a focal collection of vascular contrast which decreases in attenuation on delayed images
  • "active bleeding" - focal or diffuse collection of vascular contrast which increases in size or attenuation on a delayed phase

Imaging Technique

The AAST guidelines recommend dual arterial/portal venous phase imaging for evaluation of a vascular injury of liver, spleen, or kidney .

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu AAST liver injury scale: