Liver Injury Grading Scale

The Organ Injury Scaling (OIS) Committee’s classification of liver trauma:

Grade I
Haematoma: Subcapsular, nonexpanding, < 10% surface area.
Laceration: Capsular tear, nonbleeding, < 1cm deep.

Grade II
Haematoma: Subcapuslar, nonexpanding, 10-50% surface area; intraparenchymal, nonexpanding, < 2cm diameter.
Laceration: Capsular tear, active bleeding; 1-3cm deep, < 10cm in length.

Grade III
Haematoma: Subcapsular, > 50% surface area or expanding; ruptured subcapsular haematoma with active bleeding.
Laceration: Intraparenchymal haematoma > 2cm or expanding; > 3cm deep.

Grade IV
Haematoma: Ruptured intraparenchymal haematoma with active bleeding.
Laceration: Parenchymal disruption involving 25-50% of hepatic lobe.

Grade V
Laceration: Parenchymal disruption involving > 50% of hepatic lobe.

Grade VI
Vascular: Juxtahepatic venous injury;  ie. Retrohepatic vena cava / major hepatic veins, hepatic avulsion.

Reference

Rizoli SB, Brenneman FD, Hanna SS, Kahnamoui K. Classification of liver trauma. HPB Surg 1996; 9: 235-8.