Aortic Aneurysm

An aortic aneurysm is an abnormal bulge in the wall of the aorta, the body's largest artery. Roughly the diameter of a garden hose, this artery extends from the heart down through the chest and abdominal region, where it divides into blood vessels that supply each leg. Smaller arteries branch off to supply blood to the vital organs. Aneurysms can develop anywhere in the aorta, but most occur in the abdominal area.

Aortic aneurysms may be caused by the wear-and-tear processes of aging, especially among people who smoke or have high blood pressure; by inherited conditions that weaken the aorta, such as Marfan syndrome or familial thoracic aortic aneurysm disease; or trauma. One type of aneurysm (aortic dissection) is caused by a splitting of the wall of the aorta.

Diagnosis

In some cases, aortic aneurysms are diagnosed from a routine chest X-ray or chest CT scan taken to evaluate another condition, such as lung disease. Some abdominal aortic aneurysms are noticed by a physician who feels a pulsating bulge in the abdomen during a physical exam.

Abdominal aortic aneurysms may be evaluated further by ultrasound or CT scanning. Thoracic aortic aneurysms are typically evaluated by echocardiography, CT scanning or magnetic resonance imaging (MRI). Occasionally, a test called an aortogram is required. Test results are generally available within 24 hours in Mayo's state-of-the-art electronic medical record.

Treatment

Monitoring
If the aneurysm is small and there are no symptoms (for example, if the aneurysm is found during a routine physical examination or discovered in tests for another condition), a physician may recommend watching and waiting. An ultrasound or echocardiogram, CT scan, or MRI scan once or twice a year is a common monitoring strategy.

Medication
If the aneurysm is small, medication may be recommended to prevent enlargement or complications. Anti-hypertensives such as beta-blockers may be used to lower blood pressure.

Surgery
Surgery becomes an option when an aneurysm enlarges enough that the danger of rupture exceeds the risks to the patient from surgery.

Open Abdominal or Open Chest Surgery
An accepted standard surgical treatment for aneurysm is replacement of the damaged portion of the aorta with an artificial graft. Typically, the graft is made from Dacron, a material that will not wear out. The graft is sewn in place with permanent sutures.

Endovascular surgery
The operation, including the incision, depends on the location of the aneurysm. If the aneurysm is confined to the abdomen, then an incision either in the abdomen or on the side or flank may be used. If the aneurysm is in the chest close to the aortic valve, an incision in the front of the chest, such as a median sternotomy, may be used. If the aneurysm is in the aortic "root" and involves the valve, the aortic valve may have to be repaired or replaced. Surgery on the aortic arch is also usually done from the front. If the aneurysm involves the descending thoracic aorta, which lies in the left chest, or the thoracic and abdominal aorta, an incision on the left side of the chest will likely be required.