The American Association for the Surgery of Trauma (AAST) Liver Injury Grade Does Not Equally Predict Interventions in Blunt and Penetrating Trauma

Abstract

Introduction: The AAST liver injury grade has a validated association with mortality and need for operation. AAST liver injury grade is the same regardless of the mechanism of trauma.

Methods: A 5-year retrospective review of all liver injuries at an urban, level-one trauma center was performed.

Results: Totally, 315 patients were included (29% blunt, 71% penetrating). In blunt trauma, AAST grade was associated with need for laparotomy (0%, 7%, 5%, 33%, 29%, Grade 1-5, p = 0.01), angiography (0%, 7%, 25%, 40%, 57%, p < 0.001), embolization (0%, 7%, 15%, 33%, 43%, p = 0.01), and percutaneous drainage procedures (13% use in Grade 4, otherwise 0%, p = 0.04), but not ERCP (0% for all grades). In penetrating trauma, AAST grade was associated with need for angiography (7%, 4%, 15%, 24%, 30%, p < 0.01) and percutaneous drainage (7%, 2%, 14%, 18%, 26%, p = 0.03) and had a marginal association with embolization (0%, 4%, 11%, 13%, 22%, p = 0.06). Laparotomy, ERCP, sphincterotomy, and stenting rates increased with AAST grade, but this was not statistically significant.

Conclusion: AAST grade is associated with the need for surgical hemostasis, angioembolization, and percutaneous drainage in both penetrating and blunt trauma. Operative, endoscopic, and percutaneous procedures are utilized more in penetrating trauma. Angioembolization was used more in blunt trauma. Mechanism should be considered when using AAST grade to guide management of liver injuries.