An aneurysm is an abnormal bulge in the wall of a weakened blood vessel. If the bulge stretches out too far, the vessel may burst. The aorta is the largest artery in the body (about the size of a garden hose), and it carries blood directly from the heart, through the chest, and into the abdomen, where it splits into two leg arteries. Many arteries branch off of the aorta. An aneurysm in the aorta is called an aortic aneurysm. An aortic aneurysm may be located in the chest (thoracic aneurysm) or the abdomen (abdominal aortic aneurysm or AAA). This potentially life-threatening condition is classified by its shape, its location on the aorta, and how it is formed.
What Causes an Aneurysm?
Any condition that weakens arterial walls can lead to an aneurysm, including atherosclerosis, high blood pressure, and smoking. Deep wounds, traumatic injuries, or infections can also cause arterial damage. In some cases, an aneurysm may be congenital (present at birth). Certain inherited diseases, such as Marfan syndrome, can also increase the risk for developing an aneurysm.
Most aortic aneurysms have no symptoms and are often discovered by accident. When they do cause symptoms, it is often because the aneurysm is pressuring an organ, nerve, tissue, or nearby anatomic structure or because it begins to leak. In these cases, symptoms may include shortness of breath, a croaky or raspy voice, backache, pain in the left shoulder, or pain between the shoulder blades. An aortic aneurysm in the abdominal area may cause localized pain or tenderness, a throbbing or pulsating sensation or mass, nausea, vomiting, upset stomach, anxiety, and loss of appetite.
Aneurysms can be detected by physical examination, on a basic chest or stomach x-ray, or by using ultrasound. The size and location can be determined by echocardiography or other imaging techniques, such as arteriography, aortic angiography, magnetic resonance imaging (MRI), or computed tomography (CT) scanning.
Treatment depends on the size and location of the aneurysm and the patient’s overall health. Ascending aorta aneurysms are usually immediately repaired surgically. Other aneurysms are not as life threatening, and may be watched for varying periods, depending on their size. If they become 5 cm (almost 2″) in diameter, continue to grow, or become symptomatic, surgery may be needed to prevent the aneurysm from bursting. Surgery may involve replacing the weakened section of the aorta with an artificial synthetic fabric tube (a graft). Some types and locations of aneurysms may be treated less invasively with a percutaneously deployed stent.
Texas Heart Institute www.texasheartinstitute.com/HIC/Topics/Cond/pvd.cfm
The Society of Thoracic Surgeons www.sts.org/sections/patientinformation/aneurysmsurgery/aorticaneurysms/index.html
Medline Plus www.nlm.nih.gov/medlineplus/ency/article/001119.htm
American Heart Association www.americanheart.org/presenter.jhtml?identifier=4455