Once blood is oxygenated at the lungs, it returns to the heart which then pushes this oxygen-rich blood throughout the body. The aorta is the large artery that carries this blood from the heart and distributes it throughout the body via various branches. If the aorta is compromised in any way then the distribution of oxygen throughout the body is also impaired to some degree. There are various diseases of the aorta but one of the more serious is an aortic dissection. It can lead to death within a short period of time, depending on the severity.
What is an aortic dissection?
An aortic dissection is a tear in the wall of the aorta. This is not usually a full tear through the wall. Instead the tear occurs between the inner and middle layers of this large artery. There is nevertheless a risk of a a full tear (rupture) occurring. When the aorta bursts (ruptures), it cannot maintain blood pressure or keep blood within its walls. This can be fatal within minutes.
There are different types of aortic tears, depending on where it occurs in the aorta. Symptoms usually arise suddenly and is often mistaken for other cardiac conditions, like a heart attack. It is more likely to occur when the aorta has to deal with greater force or is abnormally weakened, either during course of life or from defects present since birth. Treatment does not always involve surgery.
Causes of Aorta Tear
The aorta is a large artery with a thick wall. This is necessary for it to handle a large volume of blood exiting the heart and contend with high pressure. However, there are several reasons why the inner lining of the wall can be compromised. This can cause the inner lining to tear. The blood under high pressure may then enter the wall of the aorta and create a channel for the blood between the inner and middle layer.
It is more likely to occur if the blood pressure rises to levels that are too high. Another factor is that wall of the aorta may be weakened. However, in most cases the blood may not extend beyond the middle layer of the aortic wall. Fortunately this middle layer is significantly strong to withstand the high pressure for a period of time. Eventually the blood can penetrate through the middle layer and lead to a rupture of the aorta.
Blood may then pour out of the aorta from where it bursts. As a result the blood pressure cannot be maintained at normal levels and oxygen-rich blood cannot be distributed throughout the body. All cells, tissues and organs may be affected but it is the heart and brain that can lead to serious and even fatal outcomes within a short period of time. These organs are highly oxygen-sensitive and just a few minutes without sufficient oxygen can cause tissue death.
Who is at risk?
An aortic dissection is more common in men than women and the 50 to 65 year age group is at a higher risk. Usually there is one or more risk factors, including:
- Aorta defects from birth (congenital)
- Uncontrolled high blood pressure (hypertension)
- Hardened plaques in the artery wall (atherosclerosis)
- Bulging of aorta wall (aortic aneurysm)
- Prior medical/surgical techniques (iatrogenic)
- Cocaine use
- Chest injury
It is important to note that an aortic dissection can occur in younger people, particularly those with a weakened aorta due to birth defects. Overall an aortic dissection is not a common problem like other cardiovascular conditions, such as a heart attack or stroke.
What are the types of aortic dissection?
Most aortic dissections occur in the part of the aorta that arises from the heart which is known as the ascending aorta. There are two classification systems for describing the type of aortic dissection. According to the Stanford classification:
- Type A, which is a tear in the ascending aorta.
- Type B, which is a tear in the descending aorta.
The other classification system is the DeBakery system which has three types:
- Type I, which is a tear in both the ascending and descending aorta.
- Type II, which is a tear in the ascending aorta.
- Type III, which is a tear in the descending aorta.
Symptoms of Aortic Dissection
As previously mentioned, the signs and symptoms of a tear in the aorta may be similar to several other heart conditions. Some of these conditions are more common than an aortic dissection and may need to first be excluded. These signs and symptoms include:
- Chest pain that is often described as a tearing pain.
- Pain radiating to the jaw, neck, arm and/or back.
- Shortness of breath.
- Lightheaded or dizziness.
- Loss of consciousness (fainting).
- Nausea with/without vomiting.
- Excessive sweating.
- Slurred speech.
- Muscle weakness or paralysis.
- Vision problems.
- Slurred speech.
- Abdominal and/or flank pain.
Most of these symptoms resemble a heart attack. Other symptoms of an aortic dissection may also resemble a stroke. Both these conditions are a possibility as it arises from a compromised blood supply to the heart and brain, respectively.
Treatment for a Burst Aorta
An aortic dissection may be treated medically and/or surgically. It depends on the type of dissection, severity and patient’s health status. One of the priorities is to lower the blood pressure if it is elevated. Persistently high blood pressure can widen the tear and possibly lead to a rupture. Pain may also need to be managed in the short term. The drugs that may therefore be prescribed includes:
- Antihypertensive drugs to lower blood pressure, like beta blockers.
- Analgesics, like morphine, to manage pain.
Surgery may involve removing the damaged part of the aorta. Reconstruction is then necessary and this may require the use of synthetic tube. Stenting may also be helpful. With stenting, a mesh wire ring is inserted to strength and widen and the affected portion of the aorta. However, surgery may not be required for every case of an aortic dissection. Sometimes a dissection can be managed medically without the need for surgery.