Aortic lacerations or traumatic aortic rupture happens when the largest artery in the body ruptures or tears, usually from a large force, such as a traffic accident. This is usually a fatal injury because huge amounts of blood flow from the tear and the patient exsanguinates. Shock and death occur within minutes. Most victims are those from a traffic accident but a fall from a great height can also cause an injury to the aorta. Up to 18 percent of deaths due to traffic accidents are from aortic lacerations.
Most patients have no symptoms but a few will feel hoarse or will have difficulty breathing or speaking. They will have pain in the chest or in the upper back. Blood pressure rapidly decreases in spite of using intravenous fluids. X-rays can show the rupture as can a CT angiogram. These can only be done if the bleeding is minimal as the patient may die in the time it takes to do the testing.
The most common site of rupture is at the aortic isthmus, where the left subclavian artery branches from the aorta. It looks like an aneurysm on CT scan but is, in fact, a rupture. On x-ray, the mediastinum will be wide and the trachea will be displaced. If there is a nasogastric tube placed, it will be displaced as well. The aorta may tear at the point of connection to the heart and can be torn completely, resulting in almost immediate death.
Treatment of an aortic laceration includes surgery to repair it. The mortality rate for surgical repair of this condition is extremely high. The person often ends up as a paraplegic because the spinal cord is extremely sensitive to a lack of blood supply that occurs during surgery and at the time of the accident. Doctors also try to keep the blood pressure low so that less blood travels through the laceration.
Death occurs right after aortic laceration about 75-90 percent of the time. About 80-85 percent of patients will die before getting to the hospital. If the blood pressure doesn’t get too high, the patient may survive the injury.
One study looked at 142 cases of aortic dissection in which the patient died. Autopsies were done on all patients. Seventy percent of patients were male around the age of 37 years. Thirty percent were women around the age of 46 years. A total of thirty five percent of the victims had elevated blood alcohol levels. A total of 54 percent of the lacerations were found at the aortic isthmus. One hundred two victims were victims of a traffic accident. A total of 42 percent were hit broadside only and 67 percent were hit in broadside and front end collisions at the same time. Most had their lacerations at the site of the isthmus. The researchers believed that it was lateral compression of the chest wall that pushes on the aorta, causing the injury. The aorta simply shears off at the site of the isthmus. It was also believed that the use of seatbelts and airbags might lessen the number of these injuries.