AAST grade | Imaging criteria (CT findings) | Operative criteria | Pathologic criteria |
I | - Subcapsular hematoma <10% surface area
- Parenchymal laceration <1 cm in depth
| - Subcapsular hematoma <10% surface area
- Parenchymal laceration <1 cm in depth
- Capsular tear
| - Subcapsular hematoma <10% surface area
- Parenchymal laceration <1 cm
- Capsular tear
|
II | - Subcapsular hematoma 10 to 50% surface area; intraparenchymal hematoma <10 cm in diameter
- Laceration 1 to 3 cm in depth and ≤10 cm length
| - Subcapsular hematoma 10 to 50% surface area; intraparenchymal hematoma <10 cm in diameter
- Laceration 1 to 3 cm in depth and ≤10 cm length
| - Subcapsular hematoma 10 to 50% surface area; intraparenchymal hematoma <10 cm in diameter
- Laceration 1 to 3 cm depth and ≤10 cm length
|
III | - Subcapsular hematoma >50% surface area; ruptured subcapsular or parenchymal hematoma
- Intraparenchymal hematoma >10 cm
- Laceration >3 cm depth
- Any injury in the presence of a liver vascular injury or active bleeding contained within liver parenchyma
| - Subcapsular hematoma >50% surface area or expanding; ruptured subcapsular or parenchymal hematoma
- Intraparenchymal hematoma >10 cm
- Laceration >3 cm in depth
| - Subcapsular hematoma >50% surface area; ruptured subcapsular or intraparenchymal hematoma
- Intraparenchymal hematoma >10 cm
- Laceration >3 cm in depth
|
IV | - Parenchymal disruption involving 25 to 75% of a hepatic lobe
- Active bleeding extending beyond the liver parenchyma into the peritoneum
| - Parenchymal disruption involving 25 to 75% of a hepatic lobe
| - Parenchymal disruption involving 25 to 75% of a hepatic lobe
|
V | - Parenchymal disruption >75% of hepatic lobe
- Juxtahepatic venous injury to include retrohepatic vena cava and central major hepatic veins
| - Parenchymal disruption >75% of hepatic lobe
- Juxtahepatic venous injury to include retrohepatic vena cava and central major hepatic veins
| - Parenchymal disruption >75% of hepatic lobe
- Juxtahepatic venous injury to include retrohepatic vena cava and central major hepatic veins
|