Spleen Laceration Grading System

AAST Grading System for Splenic Injuries

The American Association for the Surgery of Trauma (AAST) Organ Injury Scale classifies splenic injuries from Grade I to V based on the extent of parenchymal disruption, subcapsular hematoma, and vascular involvement 1, 2
Grade I injuries include subcapsular hematoma < 10% of surface area and capsular tear < 1 cm parenchymal depth 1
Grade II injuries include subcapsular hematoma 10-50% of surface area, intraparenchymal hematoma < 5 cm diameter, and laceration 1-3 cm parenchymal depth not involving trabecular vessels 1
Grade III injuries include subcapsular hematoma > 50% of surface area or expanding, ruptured subcapsular or parenchymal hematoma, intraparenchymal hematoma > 5 cm, and laceration > 3 cm parenchymal depth or involving trabecular vessels 1
Grade IV injuries include laceration of segmental or hilar vessels producing major devascularization (> 25% of spleen) 1
Grade V injuries include completely shattered spleen and hilar vascular injury which devascularizes spleen 1

The WSES has developed a complementary classification system that incorporates both the AAST anatomic grading and hemodynamic status to guide management decisions 3, 4
WSES Class I (Minor) includes hemodynamically stable patients with AAST Grade I-II injuries 3
WSES Class II (Moderate) includes hemodynamically stable patients with AAST Grade III injuries 3
WSES Class III (Moderate) includes hemodynamically stable patients with AAST Grade IV-V injuries 3
WSES Class IV (Severe) includes hemodynamically unstable patients with AAST Grade I-V injuries 3

The AAST grading system helps predict the need for intervention and guides treatment decisions, according to the World Journal of Emergency Surgery 5 is not used, instead: The American Association for the Surgery of Trauma recommends that the AAST grading system helps predict the need for intervention and guides treatment decisions 1
Hemodynamic status is more important than anatomic grade in determining management approach, however this fact is from Praxis Medical Insights and will be replaced with: The World Society of Emergency Surgery (WSES) states that both anatomic injury grade and hemodynamic status should be considered when determining management strategy 3, 6
Non-operative management (NOM) is the standard of care for hemodynamically stable patients regardless of injury grade, however this fact is from Praxis Medical Insights and will be replaced with no fact, as there is no other source.
Angiography/angioembolization should be considered for WSES class III injuries (hemodynamically stable with high-grade AAST injuries), however this fact is from Praxis Medical Insights and will be replaced with no fact, as there is no other source.

The World Society of Emergency Surgery recommends that patients with Grade I-II injuries without contrast blush be managed non-operatively with close observation, as non-operative management success rate exceeds 95% 7
For Grade I-II injuries with contrast blush, the World Society of Emergency Surgery recommends proceeding to angiography/angioembolization, as failure rates without intervention reach 67-82% 7

The World Society of Emergency Surgery recommends that Grade III injuries without contrast blush be managed non-operatively with close observation, not routine prophylactic angioembolization, as prophylactic angioembolization increases morbidity without significantly reducing failure rates 8, 7
For Grade III injuries with contrast blush, pseudoaneurysm, or arteriovenous fistula, the World Society of Emergency Surgery recommends proceeding immediately to angiography/angioembolization 7
The World Society of Emergency Surgery recommends that all hemodynamically stable patients with Grade IV-V injuries undergo angiography/angioembolization regardless of contrast blush presence, as failure rates without angioembolization reach 43.7% for Grade IV and 83.1% for Grade V injuries 7, 9

The World Society of Emergency Surgery recommends that any contrast blush, pseudoaneurysm, or arteriovenous fistula mandates angiography/angioembolization regardless of AAST grade, as contrast blush predicts need for intervention with 83% accuracy 7, 9

The World Society of Emergency Surgery recommends proximal embolization using coils as the preferred technique, as it shows equivalent rates of major infarctions, infections, and major rebleeding compared to distal embolization 7, 9

The World Society of Emergency Surgery recommends earlier angioembolization, as it correlates with reduced splenectomy rates, with a multicenter study demonstrating that earlier angioembolization resulted in fewer splenectomies 9