An aortic aneurysm is a weak, bulging area in the wall of the aorta. The bulging develops from a weakness or defect in the aortic wall and tends to get bigger with time. The aorta is the body's largest artery. It carries blood from the heart for delivery to the rest of the body. The aorta travels through the chest (thoracic aorta) and the abdomen (abdominal aorta). Abdominal aortic aneurysms are more common than thoracic aortic aneurysms.
The greatest danger is that an aneurysm will rupture. This will cause heavy, uncontrollable bleeding (hemorrhage). Aortic aneurysms can also occur with aortic dissection. Dissection is defined as a small tear in the aortic wall. Blood from the aneurysm can leak through this tear and spread between the layers of the aortic wall, eventually leading to rupture of the vessel.
Aneurysms can develop anywhere, but are most common in the aorta, iliac artery and femoral artery.
Atherosclerosis is frequently associated with aneurysm. However, it is not thought that this disease alone causes the growth of an aneurysm. It is believed that other factors, such as high blood pressure or connective tissue disorders, must be present for an aneurysm to form.
A risk factor is something that increases your chance of getting a disease or condition. Risk factors for an aortic aneurysm include the following:
- High blood pressure
- Arteriosclerosis, atherosclerosis
- Inherited connective tissue defects (Marfan syndrome, Ehlers-Danlos syndrome)
- Polyarteritis nodosa
- Bacterial endocarditis
- Age: 60 or older
- History of heart attack
- Family members with aneurysms
- Infectious aortitis
- Great vessel arteritis (Takayasu’s disease)
- Injury to the aorta, from either a motor vehicle accident or a stab wound
The U.S. Preventive Services Task Force recommends that men aged 65 to 75 who have ever smoked be screened once for abdominal aortic aneurysm with ultrasound. This is a painless procedure that gives a picture of the abdomen using sound waves. Early detection of abdominal aortic aneurysm in this group has been shown to reduce mortality from this condition.
Many aneurysms do not have symptoms and are detected during a routine physical exam or during x-ray evaluation for another disorder.
Symptoms may occur when the aneurysm grows or disrupts the wall of the aorta. Symptoms depend on the size and location of the aneurysm and may include:
- Pain in the abdomen or in the lower back
- Boring, gnawing, constant pain occurring over hours or days
- Sudden onset of severe stabbing pain
- Unusual sensation of pulsing in the abdomen
- Cough, shortness of breath (thoracic aortic aneurysm)
- Sudden blood pressure drop, fainting (upon rupture of aneurysm)
- Difficulty swallowing
- Coughing up blood
- Weight loss
- Bowel obstruction
- Chest pain
The doctor will ask about your symptoms and medical history, and perform a physical exam. Pain is the symptom that will most likely cause you to go to the doctor. Most aortic aneurysms are discovered during a routine physical exam.
Tests may include :
- Abdominal or chest x-ray
- Abdominal or chest ultrasound
- CT scan of the abdomen or chest – a type of x-ray that uses a computer to make images of the inside of the body
- MRI scan of the abdomen or chest – a test that uses magnetic waves to make images of the inside of the body
- Transesophageal echocardiography (ECHO)– the use of ultrasound to study the heart and its vessels; a transducer, which records the information, is swallowed by the patient
- Aortography – the use of x-rays and injection of a contrast dye to make images of the heart and the aorta
- MUGA scan – a study of the heart's blood supply
- Cardiac catheterization – a tube-like instrument is inserted into the heart through a vein or artery (usually in the arm or leg) to detect problems with the heart and its blood supply
- Pulmonary function tests – a series of breathing tests to assess how well your lungs work
Treatment includes surgery or stenting.
Surgery to repair an aortic aneurysm is called aneurysmectomy. It involves removing the portion of the aorta that contains the aneurysm and replacing it with a mesh graft.
With aneurysms of the thoracic aorta, the aortic valve may also be affected and need to be replaced or repaired. If the aneurysm involves important branches of the aorta, these vessels may either be repaired or bypassed.
When deciding whether to operate, the doctor will consider :
- Your age
- Your general health
- Your symptoms
- The size of your aneurysm
- Associated disease (kidney failure, stroke, etc.)
- If the aneurysm has ruptured or not
- If you've had a recent heart attack
Depending on where the aneurysm is located and how complex it is, stenting may be done. A stent-graft is a polyester tube covered by a tubular metal web. The stent-graft is inserted through a small incision in the upper thigh into the aorta. Using x-ray, it is guided through the aorta to the site of the aneurysm. With the stent-graft in place, blood flows through the stent-graft instead of into the aneurysm, eliminating the chance of rupture.
There are no guidelines for preventing an aneurysm because the cause is not known. However, you can reduce some of your risk factors by following these recommendations:
- Eat a healthful diet, one that is low in saturated fat and rich in whole grains, fruits and vegetables.
- Don't smoke. If you smoke, quit.
- Maintain a healthful weight.
- Begin a safe exercise program as recommended by your doctor.
- Seek treatment for high blood pressure, syphilis, and other infections.
- If you have Marfan syndrome, see your doctor regularly for monitoring and CT scans.