Traumatic Aortic Disruption Index is Associated with Mortality and Urgency of Stent Grafting in Blunt Thoracic Aortic (Grade 3) Injuries.

Background: Delayed stent grafting for blunt thoracic aortic injuries (BTAIs) is current standard of care. However, given the heterogeneity of pseudoaneurysm presentations, it is currently unclear which severe BTAIs require more urgent intervention. We hypothesize that a Traumatic Aortic Disruption Index (TADI) calculation based on sagittal computed tomography angiography imaging measurements would correlate with urgency of stent grafting.

Methods: All patients at a level-1 trauma center with BTAIs over a 12-year period were identified. A TADI score was then calculated using the length of pseudoaneurysm (L), maximum width of pseudoaneurysm (W), and normal adjacent aortic diameter (NA). Patient presentation, injury characteristics, timing of stent grafting, and outcomes were then evaluated.

Results: Forty-two patients were diagnosed with BTAIs. Mean age was 37.6 years, with a median injury severity score (ISS) of 29. Overall mortality was 11.9%. TADI scores ranged from 3.6 to 158.6. Compared to patients with a TADI <28, patients with TADI >28 had similar median ISS scores (34 vs. 29, P = 0.16), and rates of both traumatic brain injury (TBI; 33.3% vs. 42.0%, P = 0.53) and nonaortic hemorrhage control procedures (44.4% vs. 33.3%, P = 0.3). TADI >28 patients had a lower initial mean systolic BP (98.5 vs. 121.9, P = 0.003), more severe hypotension (lowest systolic 77.0 vs. 91.2, P = 0.034), lower initial Glasgow Coma Scale (6 vs. 13, P = 0.039), higher mean admission lactate (4.6 vs. 3.3, P = 0.036), and higher overall mortality (23.8% vs. 0%, P = 0.048). Patients with TADI >28 received stent grafting at significantly shorter median time intervals from injury identification (median 4 hrs vs. 14 hrs, P = 0.001). Overall causes of mortality were aortic hemorrhage related (n = 3, 60%) and TBI (n = 2, 40%).

Conclusions: This simple-to-calculate index is independently correlated with mortality and urgency of stent grafting in blunt trauma patients with similar ISS. Patients with TADI scores >28 were more likely to undergo urgent stent grafting, thereby suggesting a trend in practice patterns with higher scores representing injuries that should be considered for expedited operative management. The TADI score should be validated in a larger sample of blunt trauma patients as an injury prioritization tool in the multisystem injured patient.