Liver injuries are graded I-VI with increasing severity having higher grading (e.g. grade VI injuries are not salvageable).

• Grade I:
• Hepatic subcapsular hematoma of <10% surface area
• Hepatic capsular tear/laceration <1 cm in parenchymal depth
• Grade II:
• Hepatic subcapsular hematoma of 10-50% surface area
• Intraparenchymal hematoma <10 cm diameter
• Hepatic laceration 1-3 cm parenchymal depth, <10 cm length
• Grade III:
• Hepatic subcapsular hematoma of >50% surface area or expanding
• Ruptured hepatic subcapsular or parenchymal hematoma
• Intraparenchymal hematoma >10 cm diameter or expanding
• Hepatic laceration of >3 cm parenchymal depth
• Grade IV:
• Hepatic laceration with parenchymal disruption of >25-75% of hepatic lobe or 1-3 Coinaud's segments in a single lobe
• Grade V:
• Hepatic laceration with parenchymal disruption of >75% of hepatic lobe or >3 Coinaud's segments within a single lobe
• Juxtahepatic venous injury (retrohepatic vena cava or central major hepatic veins)
• Grade VI:
• Hepatic avulsion

Note that one grade increase is indicated for multiple injuries to the liver up to a grade of III.

References:

Moore EE, Cogbill TH, Jurkovich GJ, Shackford SR, Malangoni MA, Champion HR. Organ injury scaling: spleen and liver (1994 revision). J Trauma. 1995;38(3):323-4.

Trauma.org. Organ Injury Scaling: Liver. http://www.trauma.org/archive/scores/ois-liver.html. Last accessed June 13, 2013.