AAST grade of liver injury is not the single most important consideration in decision making for liver trauma

Background The liver is one of the most injured organs in both blunt and penetrating trauma. The aim of this study was to identify whether the AAST liver injury grade is predictive of need for intervention, risk of complications and mortality in our patient population, and whether this differs between blunt and penetrating-trauma mechanisms. Methods Retrospective review of all liver injuries from a single high-volume metropolitan trauma centre in South Africa from December 2012 to January 2022. Inclusion criteria were all adults who had sustained traumatic liver injury. Patients were excluded if they were under 15 years of age or had died prior to operation or assessment. Statistical analysis was undertaken using both univariate and multivariate models. Results 709 patients were included, of which 351 sustained penetrating and 358 blunt trauma. Only 24.3% of blunt compared to 76.4% of penetrating trauma patients underwent laparotomy (p < 0.001). In blunt trauma, increasing AAST grade correlated directly with rates of laparotomy with an odds ratio of 1.7 (p<0.001). In penetrating trauma, there was no statistical significance between increasing AAST grade and the rate of laparotomy. The rate of bile leak was 4.5% (32/709) and of rebleed was 0.7% (5/709). Five patients underwent ERCP and endoscopic sphincterotomy for bile leak, and three required angio-embolization for rebleeding. Increasing AAST grades were significantly associated with the odds of bile leak in both blunt and penetrating trauma. There was a statistically significant increase in the odds of a rebleed with increasing AAST grade in penetrating trauma. Five patients rebled, of which three died. Seven patients developed hepatic necrosis. Seventy-six patients died (10%). There were 34/358 (9%) deaths in the blunt cohort and 42 /351 (11%) deaths in the penetrating trauma cohort. Conclusion AAST grade in isolation is not a good predictor of the need for operation in hepatic trauma. Increasing AAST grade was not found to correlate with increased risk of mortality for both blunt and penetrating hepatic trauma. In both blunt and penetrating trauma, increasing AAST grade is significantly associated with increased bile leak. The need for ERCP and endoscopic sphincterotomy to manage bile leak in our setting is low. Similarly, the rate of rebleeding and of angioembolization was low.