During the study period, 92 cases of severe blunt liver injury (AAST Grade ≥ III) were admitted, of which 30 chose NOM without TAE for initial treatment; therefore, 62 cases (8 OM and 54 TAE) were included in the analysis dataset. Four OM cases were treated with damage control surgery without CT scanning because of nonresponse to the initial infusion therapy (Fig. 1). The median age in this study population was 29.5 (interquartile range [IQR] 20–54). The mechanism of injury was traffic accident (n = 50, 81%), fall (n = 9, 14%), and compression trauma (n = 3, 5%); in this study population, the AAST grades were III in (n = 36, 58%), IV in (n = 21, 34%), and V (n = 5, 8%). The mean ISS was 26.6 ± 13.5. There were 4 (6%) deaths on admission, 2 (3%) clinical failures, 18 (29%) massive transfusions, and 34 complications in total. The median ICU stay of patients in this study population was 5.5 (IQR 3–12) days.
Comparison of the OM and TAE groups showed statistically significant differences with regard to the mechanism of injury (p = 0.02), blood pressure on arrival (OM 98.3 mmHg vs. TAE 125.9 mmHg, p = 0.01), GCS score on arrival (OM 9.5 vs. TAE 15, p = 0.04), BE (OM − 7.8 vs. TAE − 2.6, p < 0.01), ISS (OM 37.5 vs. TAE 24.9, p = 0.01), TRISS (OM 0.78 vs. TAE 0.96, p = 0.05), time from arrival to OM/TAE (OM 120.0 min vs. TAE 76.1 min, p = 0.02), time for OM or TAE (OM 146.5 min vs. TAE 29.4 min, p < 0.01), and hemodynamically instability (OM 88% vs. TAE 28%, p < 0.01) (Table 1). Outcomes were statistically significant for length of ICU stay (OM 20.5 days vs. TAE 5 days, p = 0.01) and massive transfusion (OM 75% vs. TAE 22%, p < 0.01). Clinical failures included one case each in the OM (death due to hemorrhage) and TAE (hypotension during IR that revealed a portal vein injury, with good postoperative outcome). Deaths in the TAE group were due to cancer, cerebral infarction, and sepsis.
In the TAE group, we further compared the subgroups of patients who were unstable and stable and found statistically significant differences (Table 2) in the AAST grade (p = 0.05), admission blood pressure (stable 133.0 mmHg vs. unstable 107.3 mmHg, p < 0.01), BE (stable − 1.6 vs. unstable − 4.9, p < 0.01), ISS (stable 21.5 vs. unstable 33.9, p < 0.01), and TRISS (stable 0.98 vs. unstable 0.91, p = 0.02). Outcomes were statistically significant for length of ICU stay (stable 4 days vs. unstable 8 days, p < 0.01) and massive transfusion (stable 10% vs. unstable 53%, p < 0.01).
On univariate analyses of outcomes, only the GCS score (OR 0.65, p < 0.01) showed statistical significance for in-hospital mortality. However, multivariate analysis with GCS, age, and TAE as objective variables found that the GCS score (OR 0.48, p < 0.01) and age (OR 1.08, p = 0.04) were statistically significant factors.
The GCS (OR 0.83, p = 0.04), BE (OR 0.83, p = 0.04), ISS (OR 1.08, p < 0.01), hemodynamic instability (OR 7.03, p < 0.01), and TAE (OR 0.08, p < 0.01) showed statistical significance on univariate analysis for length of ICU stay > 7 days; however, in multivariate analysis adjusted for multicollinearity, only hemodynamic instability (OR 3.80, p = 0.05) showed statistically significant associations.
With regard to massive transfusion, systolic blood pressure (SBP) on arrival (OR 0.97, p < 0.01), the GCS score (OR 0.79, p = 0.01), BE (OR 0.84, p = 0.02), fibrinogen (OR 0.99, p = 0.01), ISS (OR 1.18, p < 0.01), hemodynamic instability (OR 15.8, p < 0.01), and TAE (OR 0.10, p < 0.01) showed statistical significance on univariate analysis. However, only hemodynamic instability (OR 7.25, p = 0.01) showed statistically significant associations on multivariate analysis accounting for multicollinearity. Only severe liver injury (grades IV and V; OR 6.61, p < 0.01) showed statistically significant associations for the development of complications (Table 3) on univariate and multivariate analysis.