Aortic injury in vehicular trauma.

A 5-year retrospective study of 530 motor vehicle fatalities revealed 105 aortic injuries occurring in 90 victims. These were reviewed to determine the injury patterns, circumstances, and mechanisms involved. In addition, the survival time, the driver's age and sex, the time of day of the accident, and the blood alcohol level were considered. The aortic injuries consisted of 61 transections and 44 tears (13% were multiple). Sixty-five percent of the injuries were located in the proximal descending aorta (66% of these were transections), 14% were in the ascending aorta and arch (33% of these were transections), 12% were in the distal descending aorta (more than 1 cm distal to the subclavian artery) (46% of these were transections), and 9% were in the abdominal aorta (56% of these were transections). Associated injuries consisted of multiple rib fractures (78%), liver lacerations (61%), head injuries (42%), first rib fractures (42%), splenic lacerations (36%), heart lacerations (34%), sternal fractures (28%), cervical spine fractures (26%), and thoracic spine fractures (20%). Death occurred within 1 hour in 94% and within 24 hours in 99%. The impact was head-on in 62% of the accidents. The victim was the driver 74% of the time and male in 77% of the cases, and the blood alcohol level exceeded 0.1 mg/dL in 43%. Most aortic disruptions were complete transections of the proximal descending aorta, associated with serious injury to the thorax, and occurred in head-on collisions. Findings support a compression and upward thrust of the heart as a mechanism responsible for the aortic disruption.