AAST liver injury scale

The 2018 revision of the AAST (American Association for the Surgery of Trauma) liver injury scale is the most widely used liver injury grading system (imaging) at the time of writing (late 2018) 3


  • 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)

N.b. advance one grade for multiple injuries up to grade III.

See also

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Article information

rID: 1596
Tag: trauma, refs
Synonyms or Alternate Spellings:
  • Hepatic injury grading
  • Liver injury grading
  • Liver trauma grading
  • Grading of liver trauma
  • Liver trauma grade

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Cases and figures

  • Figure 1: diagram
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  • Case 1: grade I
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  • Case 2: grade II
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  • Case 3: grade II
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  • Case 4: grade III
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  • Case 5: grade IV
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  • Case 6: grade V
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