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AAST Spleen Injury Scale

AAST-OIS 2018 revision (Kozar et al.)

Grades splenic trauma on CT with the 2018 revision of the AAST organ injury scale, in which any splenic vascular injury is at least grade IV.

Also searched as: trauma · splenic · injury grading · CT · splenic injury · grading

CT findings present (select all that apply)

The highest-grade applicable finding determines the AAST grade.

Multiple separate splenic injuries are present

2018 rule: advance one grade for multiple injuries, but not beyond grade III.

Lower concern
No injury findings selected
  • None of the listed findings is present — on this assessment the organ shows no traumatic injury pattern, so no AAST grade applies (grade I is the mildest injury).
  • If any listed finding is present, select it; the single highest-grade criterion determines the AAST grade.

How this tool works

The AAST spleen injury scale classifies splenic trauma from grade I (small subcapsular hematoma or superficial capsular tear) to grade V (shattered spleen or bleeding beyond the splenic capsule). A key change in the 2018 revision is that any injury accompanied by a splenic vascular injury (pseudoaneurysm or arteriovenous fistula) or by active bleeding confined within the splenic capsule is grade IV; bleeding extending into the peritoneum is grade V. Hematoma size thresholds (<10%, 10-50%, >50% surface area; <5 or >=5 cm intraparenchymal) and laceration depth thresholds (<1, 1-3, >3 cm) define grades I-III. The highest applicable finding sets the grade, and multiple injuries advance the grade by one, up to grade III.

Clinical questions that use this

Vetting guides that reach for this tool.