What is an aortic aneurysm?
An aortic aneurysm occurs when the walls of the aorta, which are typically strong and elastic in order to withstand the stress of blood flow from the heart, begin to weaken. Over time, the aortic walls lose their elasticity and expand outwards. As the weakened wall deteriorates and the damaged tissue grows in size, the risk of a more serious tear, known as an aortic dissection, or an aortic rupture, increases.
An aortic aneurysm can occur anywhere in the aorta, including at the aortic root, which may involve damage to the aortic valve, the aortic arch, the descending thoracic aorta, or the abdominal aorta.
How common is an aortic aneurysm?
Aortic aneurysms have an incidence of 5-10 cases per 100,000 in the United States, and are more common in men over the age of 60. Though aortic aneurysms do not directly cause death, complications arising from an aneurysm – such as dissection or rupture – cause approximately 15,000 deaths annually. Recently, the decline in smoking and use of cholesterol-regulating medications has decreased the incidence of aortic aneurysms.
Aortic Aneurysm Causes
What are the causes of aortic aneurysm?
There are numerous causes to aortic aneurysms, from genetic predispositions to lifestyle factors. One of the major factors is age; over time, the aorta naturally loses its elasticity, which can lead to aneurysm. Some other causes that increase the likelihood of an aneurysm developing include:
- Hypertension, or high blood pressure
- Atherosclerosis, or hardening of the aortic walls
- Hypercholesterolemia, or high cholesterol
- Infections, such as endocarditis
- Injury to the chest or stomach
- Genes associated with aortic aneurysms include ACTA2, FBN1, MYH11, and TFFBR1/2.
There appears to be a familial component to the development of aortic aneurysms, as well. Having a relative with an aortic aneurysm significantly increases the risk of developing one. Certain inherited connective tissue disorders such as Marfan’s syndrome can also weaken aortic walls, increasing the risk of aneurysm.
Aortic Aneurysm Symptoms
What are the symptoms of aortic aneurysm?
Aortic aneurysms are typically asymptomatic, and are often discovered during routine exams for other diseases. Symptoms may appear if the aneurysm expands and compresses adjoining organs, causing pain or discomfort.
Aortic aneurysms are separated into two categories, thoracic, which involves the ascending aorta, the aortic arch, and the first part of the descending aorta, and abdominal, which involves the descending aorta. Symptoms for thoracic and abdominal aortic aneurysms are different.
The symptoms of a thoracic aortic aneurysm include:
- Chest or back pain
- Dysphasia, or difficulty swallowing
The symptoms of an abdominal aneurysm include:
- Abdominal pain
- A pulsing sensation in the stomach
If an aortic aneurysm tears and causes an aortic dissection, the symptoms will appear suddenly and are much more serious. Pain will be sudden and intense, and there will be a drop in blood pressure. Dizziness and nausea may also occur. A dissection is a medical emergency, and experiencing any of these symptoms is a sign to visit the emergency room.
Aortic Aneurysm Diagnosis
How is an aortic aneurysm diagnosed?
Because aortic aneurysms are typically asymptomatic, it can be difficult to identify them before there are complications, such as blood clots or a more serious rupture. Many aortic aneurysms are diagnosed during routine testing for other medical conditions, including x-rays of the chest. Because smoking and age are risk factors for aortic aneurysms, preventative screening is recommended for male smokers above the age of 65. Men with a family history of aortic aneurysms are also recommended for preventative screening, starting at age 60.
If an aortic aneurysm is suspected, the diagnosis can be confirmed using specialized procedures such as an echocardiogram, a CT scan, or an MRI.
Aortic Aneurysm Treatment
What is the treatment for aortic aneurysm?
There are two major treatments for aortic aneurysm. Aneurysms smaller than 5 centimeters generally do not need surgical treatment. Certain medications, such as beta blockers or calcium channel blockers, may be prescribed to reduce the risk of dissection or rupture.
Any aneurysm larger than 5 centimeters, however, may require surgery; in the case of aortic root aneurysms, which may place pressure on and disrupt the functioning of the aortic valve, repairing or replacing the valve may also be necessary.
There are numerous surgical options, including open and endovascular, depending on the type of aneurysm and whether a more simple repair or more extensive replacement required. During surgery, the damaged section of the aorta is replaced with a graft or repaired with a stent, which provides structural support for the aneurysm and reduces the risk of further complications.