OBJECTIVES:Blunt aortic injury (BAI) is among the leading causes of death in trauma patients. Current guidelines recommend surgery for aortic injuries grade III and IV. However, mid-term outcome data is lacking for characteristics suggestive of improved survival, and standardized recommendations for intervention are weak. We sought to evaluate the mid-term outcome and characteristics associated with survival in patients with BAI. METHODS: This was a multi-centered retrospective cohort study of BAI from 2010 to 2020. Patients were identified from 5 tertiary level 1 trauma centers across the US, and data abstraction was performed using institutional trauma or administrative database. The primary endpoint was 2-year survival. The cohort was divided into “Surgical” vs “Non-surgical” treatment groups. Independent samples t-test, and Chi square test were used to compare patient characteristics. Kaplan-Meier survival curves were generated, and log-rank test was used to assess differences in survival based on management. Multivariable Cox proportional hazard regression was performed to identify variables associated with survival. RESULTS:A total of 235 patients were identified with a mean ISS of 37. There were 48 patients (20%) deceased before any intervention, and 19(8%) dead within 30 days. 119 patients received surgical intervention and 68 underwent non-surgical treatment. The surgical group had a higher rate of hypotension on arrival (36% vs. 18%, P<0.01), higher ISS (35 ±13 vs 28 ±11, p<0.001), and higher aortic injury grade(P<0.01). The majority (89%) of surgical patients were intervened within 24 hours of injury, and 91% had aortic injury grade of III/IV compared to 15% in the non-surgical group. Endovascular therapy was the most common surgical approach (88%). The 2-year cumulative survival for the entire cohort was 62%, and similar between surgical and non-surgical patients (p=0.95). Age<65 years (aHR [95% CI]: 0.38 [0.22-0.66], p<0.001) and lower ISS (aHR [95% CI]: 0.96 [0.95-0.98], p<0.001) were independent predictors of 2-year survival after adjusting for confounders. CONCLUSIONS:This study highlights high mortality rate of BAI, particularly in older patients with high ISS, and supports aggressive endovascular intervention for aortic injury grade III and IV. Guideline-adherence approach yields similar mid-term survival between surgery and medical interventions despite unfavorable baseline characteristics in the surgical group.