Grading system is done referring to CT scan results according to the American Association for the Surgery of Trauma (AAST) Organ Injury Scale. as follows:
Grade 1
Hematoma, subcapsular, less than 10% surface area
Laceration, capsular tear, less than 1 cm parenchymal depth
Grade 2
Hematoma, subcapsular, 10% to 50% surface area
Intraparenchymal, less than 5 cm in diameter
Laceration, capsular tear, 1 cm to 3 cm parenchyma depth that does not involve a trabecular vessel
Grade 3
Hematoma, subcapsular, more than 50% surface area expanding; ruptured subcapsular or parenchymal hematoma; intraparenchymal hematoma 5 cm or greater and expanding.
Laceration, greater than 3 cm parenchymal depth or involving trabecular vessels
Grade 4
Laceration involving segmental or hilar vessels producing major devascularization (more than 25% of spleen)
Grade 5
Laceration, completely shattered spleen
Vascular, Hilar vascular injury that devascularizes the spleen.
