The epidemiology of thoracic aortic injuries in pedestrians

Background: Traumatic rupture of the thoracic aorta is recognized as a common cause of occupant death after rapid deceleration in motor vehicle collisions. The incidence of thoracic aorta rupture in pedestrian victims of vehicular collisions, however, is unknown. This study focuses on the epidemiology of injury to the thoracic aorta in pedestrian vehicular collisions. Methods: We performed a retrospective analysis of all pedestrian fatalities and survivors of rupture of the thoracic aorta during a 6-year period at a regional Level I trauma center and medical examiner's office. Results: There were 220 pedestrian fatalities during the study period. Laceration of the thoracic aorta was noted in 28 of the 220 pedestrian victims (12.7%), Two additional pedestrians survived laceration of the thoracic aorta, for a mortality of 94%. Hospital mortality was 66% (4 of 6), The comparative hospital mortality for patients with rupture of the thoracic aorta secondary to motor vehicle collision was 42%. Conclusion: The incidence of thoracic aortic injury in pedestrian fatalities of 12.7% is comparable with previous reports of motor vehicle collision fatalities. Because of the presence of increased associated injuries, pedestrians have a significantly higher mortality. Severely injured pedestrians are at a similar risk to motor vehicle occupants for a life-threatening injury of the thoracic aorta.