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).
- haematoma: subcapsular, <10% surface area
- laceration: capsular tear, <1 cm parenchymal depth
- haematoma: subcapsular, 10-50% surface area
- haematoma: intraparenchymal <10 cm diameter
- laceration: capsular tear 1-3 cm parenchymal depth, <10 cm length
- haematoma: subcapsular, >50% surface area of ruptured subcapsular or parenchymal haematoma
- haematoma: intraparenchymal >10 cm or expanding
- laceration: capsular tear >3 cm parenchymal depth
- laceration: parenchymal disruption involving 25-75% hepatic lobe or involves 1-3 Couinaud segments
- 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)
- vascular: hepatic avulsion
N.b. advance one grade for multiple injuries up to grade III.
- 1.The American Association for the Surgery of Trauma - Injury Scoring Scale [website]
- 2. Tinkoff G, Esposito TJ, Reed J et-al. American Association for the Surgery of Trauma Organ Injury Scale I: spleen, liver, and kidney, validation based on the National Trauma Data Bank. J. Am. Coll. Surg. 2008;207 (5): 646-55. doi:10.1016/j.jamcollsurg.2008.06.342 - Pubmed citation