AAST spleen injury scale

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

The 2018 update incorporates "vascular injury" (i.e. pseudoaneurysmarteriovenous fistula) into the imaging criteria for visceral injury 4.

  • grade I
  • grade II
    • subcapsular hematoma 10-50% of surface area
    • intraparenchymal hematoma <5 cm
    • parenchymal laceration 1-3 cm in depth
  • grade III
    • subcapsular hematoma >50% of surface area
    • ruptured subcapsular or intraparenchymal hematoma ≥5 cm
    • parenchymal laceration >3 cm in depth
  • grade IV
    • any injury in the presence of a splenic vascular injury* or active bleeding confined within splenic capsule
    • parenchymal laceration involving segmental or hilar vessels producing >25% devascularisation
  • grade V
    • shattered spleen
    • any injury in the presence of splenic vascular injury* with active bleeding extending beyond the spleen into the peritoneum
  • 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

The AAST guidelines recommend dual arterial/portal venous phase imaging for evaluation of vascular injury of liver, spleen, or kidney 4.

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Article information

rID: 2074
Synonyms or Alternate Spellings:
  • AAST splenic injury grading system
  • Grading of splenic injury

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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 III
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  • Case 4: grade IV
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  • Case 5: grade IV
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  • Case 6: grade V
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  • Case 7: grade V
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