Abstract

Injury of the thoracic aorta refers to any injury which affects the portion of the aorta which lies within the chest cavity. Injuries of the thoracic aorta are usually the result of physical trauma; however, they can also be the result of a pathological process. The main causes of this injury are deceleration (such as a car accident) and crush injuries.

Classification

There are inconsistencies in the terminology of aortic injury. There are several terms which are interchangeably used to describe injury to the aorta such as "tear", "laceration", "transection", and "rupture". "Laceration" is used as a term for the consequence of a tear, whereas a "transection" is a section across an axis or cross section. For all intents and purposes, the latter is used when a tear occurs across all or nearly all of the circumference of the aorta. "Rupture" is defined as a forcible disruption of tissue. Some disagree with the usage of "rupture" as they believe it implies that a tear is incompatible with life; however, the term accurately gauges the severity of tears in the aorta. A rupture can be either complete or partial, and can be classified further by the position of the tear.

Causes

Injuries to the aorta are usually the result of trauma, such as deceleration and crush injuries. Deceleration injuries almost always occur during high speed impacts, such as those in motor vehicle crashes and falls from a substantial height. Several mechanical processes can occur and are reflected in the injury itself. A more recently proposed mechanism is that the aorta can be compressed between bony structures (such as the manubrium, clavicle, and first rib) and the spine. In the ascending aorta (the portion of the aorta which is almost vertical), one mechanism of injury is torsion (a two-way twisting).