The AAST Liver injury grading system is as follows
- grade I :
- grade II :
- haematoma: sub capsular, 10 - 50% surface area
- haematoma : intraparenchymal < 10cm diameter
- laceration: capsular tear, 1 - 3cm depth, < 10cm length
- grade III :
- haematoma : sub capsular, > 50% surface area, or ruptured with active bleeding
- haematoma : intraparenchymal > 10 cm diameter
- laceration : capsular tear, > 3 cm depth
- grade IV :
- haematoma : ruptured intraparenchymal with active bleeding
- laceration : parenchymal Distruption Involving 25 - 75% hepatic lobes or
- 1 - 3 segments (within one lobe)
- grade V :
- laceration : Parenchymal Distruption involving >75% helpatic lobe or
- > 3 segments (within one lobe)
- vascular : juxtahepatic venous injuries (IVC, major hepatic vein)
- grade VI : vascular : hepatic avulsion