Abdominal aortic aneurysm
Aneurysm - aortic; AAA
The aorta is the main blood vessel that supplies blood to the abdomen, pelvis, and legs. An abdominal aortic aneurysm (AAA) occurs when an area of the aorta in the abdomen becomes very large or balloons out.
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.
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.
Causes
The exact cause of an aneurysm is unknown. It occurs due to weakness in the wall of the artery. Factors that can increase your risk of having this problem include:
- Smoking
- High blood pressure
- Male sex
- Genetic factors
An abdominal aortic aneurysm is most often seen in males over age 60 who have one or more risk factors. The larger the aneurysm, the more likely it is to break open or tear. This can be life threatening.
Your blood vessels are the transport system that carries blood to and from your heart, to the rest of your body. Usually, everything runs pretty smoothly with this system, but sometimes there can be a problem. For example, one of the large blood vessels that supplies blood to your abdomen and lower body can swell up or bulge. This bulge is called an abdominal aortic aneurysm, and it can be pretty serious if it breaks open, or ruptures. Let's talk about abdominal aortic aneurysm. This is the descending aorta, one of the large blood vessels that sends blood to your abdomen and legs. Over a period of many years, this blood vessel can start to bulge. Although doctors aren't sure exactly what causes an aneurysm, they do know that it's more common in males over 60 and people who are overweight, who smoke, or who have high blood pressure or cholesterol. Eventually, if not treated, the aneurysm can pop open or rupture, and spill blood into your abdominal cavity or into the wall of the artery. If an aneurysm ruptures, it is considered a true medical emergency. So, how do you find out if you have an aneurysm? You may not realize that you have one, because often aneurysms don't cause any symptoms until they rupture. An imaging test like a CT scan or ultrasound may help in finding a suspected aneurysm. If it does break open, you may feel severe pain in your stomach. That pain may spread to your groin, buttocks, or legs. You could also feel sick to your stomach, have clammy skin, and your heart may beat faster than normal. If you have any of these symptoms, see your doctor, who can examine you. Your doctor may also recommend an imaging test to see for sure if you have an aneurysm. Treatments for aneurysms vary depending on how severe the aneurysm is. If you're not having symptoms, and your aneurysm is small and hasn't broken open, your doctor may suggest just checking it every six months to make sure it doesn't get bigger. If it's bigger than 2 inches, you'll probably need to have surgery. The goal is to perform surgery before complications and symptoms develop. The surgeon will replace the damaged, bulging section of blood vessel with a section of man-made vessel, commonly called a graft. It's better to avoid getting an aneurysm than to have to treat it. Eat a healthy diet, watch your cholesterol and blood pressure levels, and quit smoking to help prevent an aneurysm from forming in the first place. Men who are over the age of 65 and have ever smoked or who have a close relative who's had an abdominal aortic aneurysm should have one screening ultrasound done to check for an abdominal aortic aneurysm. If you're having any symptoms of an abdominal aneurysm, like severe pain in your belly or back, it's very important that you get medical help right away. Go to the emergency room or call your health care provider for immediate help. Small aneurysms are easy to treat with surgery. But once they get larger and rupture, they can be life threatening.
Symptoms
Aneurysms can develop slowly over many years, often with no symptoms. Symptoms may come on quickly if the aneurysm expands rapidly, tears open or leaks blood within the wall of the vessel (aortic dissection).
Symptoms of rupture include:
- Pain in the abdomen or back. The pain may be severe, sudden, persistent, or constant. It may spread to the groin, buttocks, or legs.
- Passing out.
- Clammy skin.
- Dizziness.
- Nausea and vomiting.
- Rapid heart rate.
- Shock.
Exams and Tests
Your health care provider will examine your abdomen and feel the pulses in your legs. The provider may find:
- A lump (mass) in the abdomen
- Pulsating sensation in the abdomen
- Stiff or rigid abdomen
Your provider may find this problem by doing the following tests:
- Ultrasound of the abdomen when the abdominal aneurysm is first suspected
- CT scan of the abdomen to confirm the size of the aneurysm
- CTA (computed tomographic angiogram) to help with surgical planning
Any one of these tests may be done when you are having symptoms.
You may have an abdominal aortic aneurysm that is not causing any symptoms. Your provider may order an ultrasound of the abdomen to screen for an aneurysm.
- Most men who are age 65 to 75, who have smoked during their life should have this test one time.
- Some men who are age 65 to 75, who have never smoked during their life may need this test one time.
Treatment
If you have bleeding inside your body from an aortic aneurysm, you will need surgery right away.
If the aneurysm is small and there are no symptoms:
- Surgery is rarely done.
- You and your provider must decide if the risk of having surgery is smaller than the risk of bleeding if you do not have surgery.
- Your provider will want to check the size of the aneurysm with ultrasound tests. The recommended frequency depends on the size of your aneurysm. Ask your provider what is best for you.
Most of the time, surgery is done if the aneurysm is bigger than 2 inches (5 centimeters) across or growing quickly. The goal is to do surgery before complications develop.
There are two types of surgery:
- Open repair - A large cut is made in your abdomen. The abnormal vessel is replaced with a graft made of man-made material.
- Endovascular stent grafting - This procedure can be done without making a large cut in your abdomen, so you may recover more quickly. This may be a safer approach if you have certain other medical problems or are an older adult. Endovascular repair can sometimes be done for a leaking or bleeding aneurysm.
Outlook (Prognosis)
The outcome is often good if you have surgery to repair the aneurysm before it ruptures.
When an abdominal aortic aneurysm begins to tear or ruptures, it is a medical emergency. Only about 1 in 5 people survive a ruptured abdominal aneurysm.
When to Contact a Medical Professional
Go to the emergency room or call 911 or the local emergency number if you have pain in your belly or back that is very bad or does not go away.
Prevention
To reduce the risk of aneurysms:
- Eat a heart-healthy diet, exercise, stop smoking (if you smoke), and reduce stress.
- If you have high blood pressure or diabetes, take your medicines as your provider has told you.
People over age 65 who have ever smoked should have a screening ultrasound done once.
References
BravermanAC, Schermerhorn M. Diseases of the aorta. In: Libby P, Bonow RO, Mann DL,Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: ATextbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier;2022:chap 42.
Colwell CB. Abdominal aortic aneurysm. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 72.
Isselbacher EM, Preventza O, Black JH 3rd, et al. 2022 ACC/AHA Guideline for the diagnosis and management of aortic disease: a report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol. 2022;80(24) e223–e393. PMID: 36334952
Owens DK, Davidson KW, Krist AH, et al. Screening for abdominal aortic aneurysm: US Preventive Services Task Force Recommendation Statement. JAMA. 2019;322(22):2211-2218. PMID: 31821437
Sharafuddin MJ. Abdominal aortic aneurysms: open surgical treatment. In: Sidawy AN, Perler BA, eds. Rutherford's Vascular Surgery and Endovascular Therapy. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 73.
Version Info
Last reviewed on: 8/22/2023
Reviewed by: Mary C. Mancini, MD, PhD, Cardiothoracic Surgeon, Shreveport, LA. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
