Rupture of the thoracic aorta by broadside impacts in road traffic and other collisions: further angiographic observations and preliminary autopsy findings.

Violent lateral blunt impacts to the chest, such as inflicted in broadside automobile collisions, can cause traumatic rupture of the thoracic aorta. Unfortunately, because this injury is among the least common in blunt chest trauma, and given that it is not caused by the expected "classic" frontal collision, its diagnosis is often delayed or altogether missed. In most of these events, quite unlike the classic isthmus rupture of deceleration accidents, the injury appears to be partial shearing of the distal aortic arch, probably just above the isthmus. The aortic injury is often part of a wounding pattern typical of a lateral collision, in which critical intra-abdominal injuries are located on the side of the patient that was on the receiving end of the impact. Findings in 13 such patients are presented and discussed. The point is also made that because seatbelts and air bags do not protect car occupants against broadside impacts, their mandatory use will not lower the rate of occurrence of aortic shearing in lateral collisions, and as a result the numerical prominence of these injuries compared with that of aortic isthmus ruptures in the statistics of road traffic collisions may be expected to increase.