AAST liver injury scale

The AAST (American Association for the Surgery of Trauma) liver injury scale 1994 revision is the most widely used grading system at the time of writing (mid 2016). 


  • grade I
    • haematoma: subcapsular, <10% surface area
    • laceration: capsular tear, <1 cm  parenchymal depth
  • grade II
    • haematoma: subcapsular, 10-50% surface area
    • haematoma: intraparenchymal <10 cm diameter
    • laceration: capsular tear 1-3 cm parenchymal depth, <10 cm length
  • grade III
    • haematoma: subcapsular, >50% surface area of ruptured subcapsular or parenchymal haematoma
    • haematoma: intraparenchymal >10 cm or expanding
    • laceration: capsular tear >3 cm parenchymal depth
  • grade IV
    • laceration: parenchymal disruption involving 25-75% hepatic lobe or involves 1-3 Couinaud segments 
  • grade V
    • laceration: parenchymal disruption involving >75% of hepatic lobe or involves >3 Couinaud segments (within one lobe)
    • vascular: juxtahepatic venous injuries (retrohepatic vena cava / central major hepatic veins)
  • grade VI
    • vascular: hepatic avulsion

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

See also

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Article Information

rID: 1596
Systems: Hepatobiliary, Trauma
Section: Classifications
Tags: 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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    Case 1: grade I
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    Case 2: grade II
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    Case 3: grade III
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    Case 4: grade IV
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    Case 5: grade V
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