AAST liver injury scale

Dr Derek Smith and A.Prof Frank Gaillard et al.

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

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    Figure 1: diagrams
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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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