What it is?
             An abdominal aortic aneurysm is when the large blood vessel that supplies blood to the abdomen, pelvis, and legs becomes abnormally large or balloons outward.


Causes, incidence, and risk factors
             The exact cause is unknown, but risk factors for developing an aortic aneurysm include:
1) Genetic factors
2) Emphysema
3) High blood pressure
4) Obesity
5) High cholesterol
6) Male gender
7) Smoking

             An abdominal aortic aneurysm can develop in anyone, but is most often seen in males over 60 who have one or more risk factors. The larger the aneurysm, the more likely it is to rupture.
             When an abdominal aortic aneurysm ruptures, it is a true medical emergency. Aortic dissection occurs when the innermost lining of the artery tears and blood leaks into the wall of the artery. This most commonly occurs in the aorta within the chest.

Symptoms
             Aneurysms develop slowly over many years and often have no symptoms. If an aneurysm expands rapidly, tears open (ruptured aneurysm), or blood leaks along the wall of the vessel (aortic dissection), symptoms may develop suddenly.

The symptoms of rupture include:
1) Anxiety Abdominal mass
2) Abdominal rigidity
3) Clammy skin
4) Nausea and vomiting
5) Pain in the abdomen or back -- severe, sudden, persistent, or constant. The pain may radiate to groin, buttocks, or legs.
6) Shock
7) Pulsating sensation in the abdomen
8) Rapid heart rate when rising to a standing position

                         

             Aortic rupture (a tear in the aorta, which is the major artery coming from the heart) can be seen on a chest x-ray. In this case, it was caused by a traumatic perforation of the thoracic aorta. This is how the x-ray appears when the chest is full of blood (right-sided hemothorax) seen here as cloudiness on the left side of the picture.

Signs and tests
             Your doctor will examine your abdomen. The exam also will include an evaluation of pulses and sensation in your legs.
Abdominal aortic aneurysm may be diagnosed with these tests:
1) Abdominal ultrasound
2) Angiography of aorta
3) CT scan of abdomen

                                       

             Abdominal aortic aneurysm involves a widening, stretching, or ballooning of the aorta. There are several causes of abdominal aortic aneurysm, but the most common results from atherosclerotic disease. As the aorta gets progressively larger over time there is increased chance of rupture.

Treatment
             If the aneurysm is small and there are no symptoms (for example, if it was discovered during a routine physical), your doctor may recommend periodic evaluation. This usually includes a yearly ultrasound, to see if the aneurysm is getting bigger.
Aneurysms that cause symptoms usually require surgery to prevent complications.
             Surgery is recommended for patients with aneurysms bigger than 5.5 cm in diameter and aneurysms that rapidly increase in size. The goal is to perform surgery before complications or symptoms develop.

There are two approaches to surgery:
1) In a traditional (open) repair, a large cut is made in your abdomen. The abnormal vessel is replaced with a graft made of synthetic material, such as Dacron.
2) The other approach is called endovascular stent grafting. An endovascular stent graft is a tube made of metal mesh that helps support the artery. Small, hollow tubes called catheters are inserted through arteries in your groin. The stent graft is sent through a catheter, and permanently placed into the artery. Endovascular stent grafting can be done without making a large cut in your abdomen, so you may get well faster. However, not all patients with abdominal aortic aneurysms can have this type of surgery.
1) Expectations (prognosis)
             The outcome is usually good if an experienced surgeon repairs the aneurysm before it ruptures. However, less than 40% of patients survive a ruptured abdominal aneurysm.

Complications
1) Heart attack
2) Aortic dissection
3) Aortic rupture
4) Arterial embolism
5) Hypovolemic shock
6) Stroke
7) Kidney failure

Calling your health care provider
             Go to the emergency room or call 911 if you develop severe abdominal pain or any of the other symptoms of an aneurysm.

Prevention
To reduce the risk of developing aneurysms:
1) Eat well
2) Exercise
3) Avoid tobacco
4) Get regular physical exams
5) Men over age 65 who have ever smoked should have a screening ultrasound performed once

Video

Reference  MedicinePlus , Medical Encyclopedia OR Live