Revised AAST scale for splenic injury (2018): does addition of arterial phase on CT have an impact on the grade?

Purpose To determine whether an additional arterial phase (AP) leads to a change in the grade of splenic injury according to the 2018 revision of the AAST Organ Injury Scale, which has incorporated vascular injuries into the grading system and also to study its impact on management. Methods In this retrospective study, 527 patients who sustained blunt abdominal trauma and had underwent dual-phase CT (AP and portal venous phase (PVP)) from December 2014 to October 2016 (23 months) were included. Two experienced radiologists independently graded the splenic injury according to the revised system in 2 blinded ways (AP + PVP and PVP alone). Receiver operator characteristic (ROC) curves were generated for grade of injury on both the phases for all splenic interventions. Results Splenic injuries were detected in 154 patients, and splenic vascular injuries were detected in 52 of them. Of these, 22 vascular injuries were detected only on the AP, leading to a change in the grade of injury according to the new system in 18 patients. The AUC for ROC curves was generated for the grade of injury on AP + PVP vs. PVP alone for angioembolization (0.80 vs. 0.71,pvalue 0.002), and all splenic interventions (0.89 vs. 0.83,pvalue 0.003) showed higher AUC for AP + PVP. Conclusion Addition of AP leads to a significant change in the grading of splenic injuries according to the revised grading system due to increased detection of vascular injuries. Accurate classification of splenic injuries using additional AP would lead to better triage of patients for splenic interventions or conservative management.