Aortic aneurysm

Symptoms

Aortic aneurysms often grow slowly and usually without symptoms, making them difficult to detect. Some aneurysms will never rupture. Many start small and stay small, although many expand over time. Some aortic aneurysms enlarge slowly, increasing less than half an inch (1.2 centimeters) a year. Others expand at a faster rate, which increases the risk of rupture. How quickly an aortic aneurysm may grow is difficult to predict.

As an aortic aneurysm grows, some people may notice:

• A pulsating feeling near the navel, if the aneurysm occurs in the abdomen
• Tenderness or pain in the abdomen or chest
• Back pain

Aneurysms can develop anywhere along the aorta, but most occur in the abdomen and are called abdominal aortic aneurysms. Aneurysms that occur in the part of the aorta that's higher up in your chest are called thoracic aortic aneurysms.

Causes

Abdominal aortic aneurysms

About 75 percent of all aortic aneurysms occur in the part of your aorta that's in your abdomen. Although the exact cause of abdominal aortic aneurysms is unknown, researchers think a number of factors can play a role, including:

• Tobacco use. Cigarette smoking and other forms of tobacco use make up one of the most significant factors involved in the development of aortic aneurysms. In addition to the damaging effects that smoking causes directly to the arteries, smoking contributes to atherosclerosis and high blood pressure, and causes aneurysms to grow faster.
• High blood pressure. High blood pressure, especially if poorly controlled, increases the risk of developing an aortic aneurysm.
• Infection in the aorta (vasculitis). In rare cases, aortic aneurysm may be caused by an infection or inflammation (vasculitis) that weakens a section of the aortic wall. There is often a pattern of aneurysm development among family members, meaning it could be genetic.

Thoracic aortic aneurysms

About 25 percent of aortic aneurysms occur higher up in your chest (the thoracic area of the aorta). While the same risk factors associated with abdominal aortic aneurysms can contribute to thoracic aortic aneurysms, there are some additional factors that can lead to a thoracic aortic aneurysm, including:

• Marfan syndrome. People who are born with Marfan syndrome, a genetic condition that affects the connective tissue in the body, are particularly at risk of a thoracic aortic aneurysm. Those with Marfan syndrome may have a weakness in the aortic wall that makes them more susceptible to aneurysm. People with Marfan syndrome often have distinct physical traits, including tall stature, very long arms, a deformed breastbone and eye problems.
• Previous injury to the aorta. You're more likely to have a thoracic aortic aneurysm if you've had previous problems with your aorta, such as a tear in the wall of the aorta (aortic dissection).
• Traumatic injury. Some people who are injured in falls or motor vehicle crashes develop thoracic aortic aneurysms.

An aortic aneurysm is different from a condition called aortic dissection. Aortic dissection often occurs in the same place many aneurysms occur. In aortic dissection, a tear occurs in the wall of the aorta. This causes bleeding into and along the aortic wall and, in some cases, completely outside the aorta (rupture). Aortic dissection is a life-threatening emergency. 

Risk factors

Aortic aneurysm risk factors include:

• Age. Abdominal aortic aneurysms occur most often in people age 60 and older.
• Tobacco use. Tobacco use is a strong risk factor for the development of an aortic aneurysm. The longer you've smoked or chewed tobacco, the greater your risk.
• High blood pressure. Increased blood pressure damages the blood vessels in the body, raising your chances of developing an aneurysm.
• Atherosclerosis. Atherosclerosis, the buildup of fat and other substances that can damage the lining of a blood vessel, increases your risk of an aneurysm.
• Being male. Men develop aortic aneurysms five to 10 times more often than women do. However, women with aortic aneurysms have a higher risk of rupture than do men.
• Race. Aortic aneurysms occur more commonly in whites than in people of other races.
• Family history. People who have a family history of aortic aneurysm are at increased risk of having one. People who have a family history of aneurysms tend to develop aneurysms at a younger age and are at higher risk of rupture.

Complications

Tears in the wall of the aorta (dissection) and rupture of the aorta are the main complications of abdominal aortic aneurysm. A ruptured aortic aneurysm can lead to life-threatening internal bleeding. In general, the larger the aneurysm, the greater the risk of rupture.

Signs and symptoms that your aortic aneurysm has burst include:

• Sudden, intense and persistent abdominal, chest or back painPain that radiates to your back or legs
• Sweatiness
• Clamminess
• Dizziness
• Low blood pressure
• Fast pulse
• Loss of consciousness
• Shortness of breath

Another complication of aortic aneurysms is the risk of blood clots. Small blood clots can develop in the area of the aortic aneurysm. If a blood clot breaks loose from the inside wall of an aneurysm and blocks a blood vessel elsewhere in your body, it can cause pain or block the blood flow to the legs, toes or abdominal organs.

Diagnosis

Ultrasound of aortic aneurysmMost abdominal aortic aneurysms are found during an examination for another reason. For example, during a routine exam, your doctor may feel a pulsating bulge in your abdomen, though it's unlikely your doctor will be able to hear signs of an aneurysm through a stethoscope. Aortic aneurysms are often found during routine medical tests, such as a chest X-ray or ultrasound of the heart or abdomen, sometimes ordered for a different reason.

If your doctor suspects that you have an aortic aneurysm, specialized tests can confirm it. These tests might include:

• Echocardiogram. This test is a sonogram of your heart. It uses sound waves to capture real-time images of your heart in motion. Echocardiograms show how well your heart chambers and valves are working. Occasionally, to better see your aorta, your doctor may recommend a transesophageal echocardiogram — in which the sound waves are generated from within your body by a device threaded down your esophagus.
• Abdominal ultrasound. This exam can help diagnose an abdominal aortic aneurysm. During this painless exam, you lie on your back on an examination table and a small amount of warm gel is applied to your abdomen. The gel helps eliminate the formation of air pockets between your body and the instrument the technician uses to see your aorta, called a transducer. The technician presses the transducer against your skin over your abdomen, moving from one area to another. The transducer sends images to a computer screen that the technician monitors to check for a potential aneurysm.
• Computerized tomography (CT) scan. This painless test can provide your doctor with clear images of your aorta. During a CT scan, you lie on a table inside a doughnut-shaped machine called a gantry. Detectors inside the gantry measure the radiation that has passed through your body and converts it into electrical signals. A computer gathers these signals and assigns them a color ranging from black to white, depending on signal intensity. The computer then assembles the images and displays them on a computer monitor.
• Magnetic resonance imaging (MRI). MRI is another painless imaging test. Most MRI machines contain a large magnet shaped like a doughnut or tunnel. You lie on a movable table that slides into the tunnel. The magnetic field aligns atomic particles in some of your cells. When radio waves are broadcast toward these aligned particles, they produce signals that vary according to the type of tissue they are. Your doctor can use the images produced by the signals to see if you have an aneurysm.

Regular screening for people at risk of abdominal aortic aneurysms

Because aortic aneurysms often don't cause symptoms, anyone age 60 and older who has risk factors for developing an aortic aneurysm should consider regular screening for the condition. Men ages 65 to 75 who have ever smoked should have a one-time screening for abdominal aortic aneurysm using abdominal ultrasound. Men age 60 and older with a family history of abdominal aortic aneurysm should also consider screening.

Screening for thoracic aortic aneurysms

Conditions that cause an aneurysm to occur higher up in your chest (thoracic aortic aneurysm) can run in families. Because of this, your doctor may recommend you have tests to check for thoracic aortic conditions if a first-degree relative, such as a sibling, son or daughter, has Marfan syndrome or another condition that could cause a thoracic aortic aneurysm. Additional tests to check for thoracic aortic aneurysms include:

• Imaging tests. Your doctor may recommend that your first-degree relatives have an echocardiogram or another type of imaging test to check for Marfan syndrome or another thoracic aortic condition. If your doctor finds you have an enlarged aorta or an aneurysm, you'll likely need another imaging test within six months to make sure your aorta hasn't grown larger.
• Genetic testing. One cause of thoracic aortic aneurysms, Marfan syndrome, is a hereditary condition. Right now, there's no genetic test that alone can definitely establish or rule out a diagnosis of Marfan syndrome. However, genetic testing can aid in the diagnosis of Marfan syndrome, especially if you do not have symptoms. In addition, you may want to consider genetic testing and genetic counseling before starting a family, to see what your chances are of passing on Marfan syndrome to your future children.

Treatments and drugs

The goal of treatment is to prevent your aneurysm from rupturing. Generally, your treatment options are medical monitoring or surgery. Your decision depends on the size of the aortic aneurysm and how fast it's growing.

Medical monitoring

If your thoracic aortic aneurysm is small, your doctor may recommend medical monitoring, which includes regular appointments to make sure your aneurysm isn't growing, and management of other medical conditions that could worsen your aneurysm.

It's likely your doctor will order regular imaging tests to check on the size of your aneurysm. Expect to have an echocardiogram at least six months after your aneurysm is diagnosed and regular exams and imaging tests after that.

If you have high blood pressure or blockages in your arteries, it's likely that your doctor will prescribe medications to lower your blood pressure and reduce your risk of complications from your aneurysm. These medications could include:

• Beta blockers. Beta blockers lower your blood pressure by slowing your heart rate. Examples of beta blockers include metoprolol, atenolol (Tenormin) and bisoprolol.
• Angiotensin II receptor blockers. Your doctor may also prescribe these medications if beta blockers aren't enough to control your blood pressure. These medications are recommended for people who have Marfan syndrome, even if they don't have high blood pressure. Examples of angiotensin II receptor blockers include losartan (Cozaar), valsartan (Diovan) and olmesartan.
• Statins. These medications can help lower your cholesterol, which can help reduce blockages in your arteries and reduce your risk of aneurysm complications. Examples of statins include atorvastatin (Lipitor), simvastatin (Zocor) and others.

If you smoke, it's important that you stop. Using tobacco can worsen your aneurysm.

Surgery to prevent rupture

If you have a thoracic aortic aneurysm, surgery is generally recommended if your aneurysm is 2.2 inches (5.6cm) and larger. If you have Marfan syndrome, another connective tissue disease or a family history of aortic dissection, your doctor may recommend surgery for smaller aneurysms as well.

Depending on your condition and the location of your thoracic aortic aneurysm, your doctor may recommend:

• Open-chest surgery. Open-chest surgery to repair a thoracic aortic aneurysm involves removing the damaged section of the aorta and replacing it with a synthetic tube (graft), which is sewn into place. This procedure requires open-abdominal or open-chest surgery, and it will take you several months to fully recover.
• Endovascular surgery. Doctors attach a synthetic graft to the end of a thin tube (catheter) that's inserted through an artery in your leg and threaded up into your aorta. The graft — a woven tube covered by a metal mesh support — is placed at the site of the aneurysm and fastened in place with small hooks or pins. The graft reinforces the weakened section of the aorta to prevent rupture of the aneurysm.
• Other heart surgeries. If another condition is contributing to your aneurysm's development, such as a problem with your heart's valves, your doctor may recommend additional surgeries to repair or replace the damaged valves to stop your aneurysm from worsening.

Emergency surgery

Although it's possible to repair a ruptured aortic aneurysm with emergency surgery, the risk is much higher and there is less chance of survival. Many people who have a ruptured aortic aneurysm die before they reach the hospital.

Lifestyle remedies

There are no medications you can take to prevent an aortic aneurysm, although taking medications to control your blood pressure and cholesterol level may reduce your risk of having complications from a thoracic aortic aneurysm.

For now the best approach to prevent an aortic aneurysm or keep an aneurysm from worsening is to keep your blood vessels as healthy as possible. That means taking these steps:

• Don't use tobacco products.
• Keep your blood pressure under control.
• Get regular exercise.
• Reduce cholesterol and fat in your diet.

If you have some risk factors for aortic aneurysm, talk to your doctor. If you are at risk, your doctor may recommend additional measures, including medications to lower your blood pressure and relieve stress on weakened arteries. You may also want to consider screening echocardiograms every few years.

References:

https://www.nlm.nih.gov/medlineplus/aorticaneurysm.html

https://en.wikipedia.org/wiki/Aortic_aneurysm

http://www.emedicinehealth.com/aortic_aneurysm/article_em.htm

http://www.medicinenet.com/abdominal_aortic_aneurysm/article.htm

http://www.irishhealth.com/article.html?con=34