Splenic injury is classified based on CT findings according to the American Association for the Surgery of Trauma (AAST) Organ Injury Scale. It is a useful scale that categorizes splenic injuries, but it does not predict the need for surgical intervention.

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, laceration involving segmental or hilar vessels producing major devascularization ( more than 25% of the spleen)

Grade 5

• Laceration, completely shattered spleen
• Vascular; a hilar vascular injury that devascularizes the spleen

References

1. Coccolini F, Montori G, Catena F, Kluger Y, Biffl W, Moore EE, Reva V, Bing C, Bala M, Fugazzola P, Bahouth H. Splenic trauma: WSES classification and guidelines for adult and pediatric patients. World Journal of Emergency Surgery. 2017 Dec;12:1-26.
2. Knipe H, Murphy A, Botz B, et al. Splenic trauma. Reference article, Radiopaedia.org (Accessed on 16 Mar 2023) https://doi.org/10.53347/rID-26342
3. Waseem M, Bjerke S. Splenic injury. InStatPearls [Internet] 2022 Jan 29. StatPearls Publishing.