Comparison of American Association for the Surgery of Trauma (AAST) and Japanese Association for the Surgery of Trauma (JAST) classification systems for predicting mortality in surgically managed liver trauma: A single-center experience.

Abstract

Background: Advances in treatment strategies and interventional radiology have led to the widespread adoption of nonoperative management for liver trauma;however, severe cases still require surgery, and are associated with high mortality. While the widely used American Association for the Surgery of Trauma (AAST) Liver Injury Scale is regularly updated and includes computed tomography (CT) findings, the Japanese Association for the Surgery of Trauma (JAST) Liver Injury Classification is also utilized in Japan but may have limitations in predicting prognosis based solely on imaging. Few studies have compared the prognostic utility of the two systems.

Methods: This retrospective study analyzed patients who underwent laparotomy for liver injury at Fukushima Medical University Hospital (2013-2023). Liver injury-related mortality cases were compared with survivors to assess the predictive accuracy of the AAST and JAST classifications.

Results: Among 23 patients, the overall mortality rate was 34.8%, with 5 liver injury-related deaths. AAST grades IV-V yielded 100% sensitivity and 80% specificity for predicting mortality (p=0.001), whereas JAST had lower sensitivity (60.0%) and specificity (86.7%, p=0.073).

Conclusion: AAST grading may be more effective than the JAST classification for predicting liver injury-related mortality. Future JAST revisions should integrate imaging findings and treatment strategies to enhance its prognostic accuracy.