Blunt thoracic aortic injuries: an autopsy study.

Objective: The objective of this study was to identify the incidence and patterns of thoracic aortic injuries in a series of blunt traumatic deaths and describe their associated injuries.

Methods: All autopsies performed by the Los Angeles County Department of Coroner for blunt traumatic deaths in 2005 were retrospectively reviewed. Patients who had a traumatic thoracic aortic (TTA) injury were compared with the victims who did not have this injury for differences in baseline characteristics and patterns of associated injuries.

Results: During the study period, 304 (35%) of 881 fatal victims of blunt trauma received by the Los Angeles County Department of Coroner underwent a full autopsy and were included in the analysis. The patients were on average aged 43 years±21 years, 71% were men, and 39% had a positive blood alcohol screen. Motor vehicle collision was the most common mechanism of injury (50%), followed by pedestrian struck by auto (37%). A TTA injury was identified in 102 (34%) of the victims. The most common site of TTA injury was the isthmus and descending thoracic aorta, occurring in 67 fatalities (66% of the patients with TTA injuries). Patients with TTA injuries were significantly more likely to have other associated injuries: cardiac injury (44% vs. 25%, p=0.001), hemothorax (86% vs. 56%, p<0.001), rib fractures (86% vs. 72%, p=0.006), and intra-abdominal injury (74% vs. 49%, p<0.001) compared with patients without TTA injury. Patients with a TTA injury were significantly more likely to die at the scene (80% vs. 63%, p=0.002).

Conclusion: Thoracic aortic injuries occurred in fully one third of blunt traumatic fatalities, with the majority of deaths occurring at the scene. The risk for associated thoracic and intra-abdominal injuries is significantly increased in patients with thoracic aortic injuries.