Aortic dissection

Overview

An aortic dissection is a serious condition in which a tear occurs in the inner layer of the body's main artery (aorta). Blood rushes through the tear, causing the inner and middle layers of the aorta to split (dissect). If the blood goes through the outside aortic wall, aortic dissection is often deadly.

Aortic dissection is relatively uncommon. It usually occurs in men in their 60s and 70s. Symptoms of aortic dissection may mimic those of other diseases, often leading to delays in diagnosis. However, when an aortic dissection is detected early and treated promptly, the chance of survival greatly improves.

different types of aortic dissection

There are two main types:

Stanford Type A Aortic Dissection: This type of dissection occurs in the first part of the aorta, closer to the heart, and can be immediately life-threatening. It usually requires emergency open chest surgery to repair or replace the first segment of the aorta where the tear started (ascending aorta +/- the arch and/or aortic valve). This is a more common type of dissection than Type B, and the dissection of the aorta usually extends through the entire length of the aorta.

Stanford Type B Aortic Dissection: This type of tear begins farther down the aorta (descending aorta beyond the arch), and farther from the heart. Like the type A dissection, this usually extends from the descending aorta into the abdominal segment (abdominal aorta), but doesn’t involve the first part of the aorta in the front of the chest. Surgery may or may not be needed immediately, depending on exactly where the dissection is located and if it is or isn’t cutting off blood flow to your organs. These operations usually can be performed with a stent-graft device inserted into the aorta.

Another classification system (DeBakey Classification) defines dissection by three types. Type 1 originates in the ascending aorta and extends through the downstream aorta. Type 2 originates and is limited to the ascending aorta (both would be considered Stanford Type A). Type 3 originates in the descending aorta and extends downward (similar to Type B).

Symptoms

• In most cases, the symptoms begin suddenly, and include severe chest pain. The pain may feel like a heart attack.
• Pain can be described as sharp, stabbing, tearing, or ripping.
• It is felt below the chest bone, and then moves under the shoulder blades or to the back.
• Pain can move to the shoulder, neck, arm, jaw, abdomen, or hips.
• The pain changes position, often moving to the arms and legs as the aortic dissection gets worse.

Symptoms are caused by a decrease of blood flowing to the rest of the body, and can include:

• Anxiety and a feeling of doom
• Fainting or dizziness
• Heavy sweating (clammy skin)
• Nausea and vomiting
• Pale skin (pallor)
• Rapid, weak pulse
• Shortness of breath and trouble breathing when lying flat (orthopnea)

Other symptoms may include:

• Pain in the abdomen
• Stroke symptoms
• Swallowing difficulties from pressure on the esophagus

Causes

An aortic dissection is caused by a weakened area of the aorta's wall.

Aortic dissections are divided into two groups, depending on which part of the aorta is affected:

Type A. This more common and dangerous type involves a tear in the part of the aorta where it exits the heart. The tear may also occur in the upper aorta (ascending aorta), which may extend into the abdomen.

Type B. This type involves a tear in the lower aorta only (descending aorta), which may also extend into the abdomen.

Risk factors

• Some of the things that may raise your risk of aortic dissection include:
• Uncontrolled high blood pressure (hypertension)
• Hardening of the arteries (atherosclerosis)
• Weakened and bulging artery (aortic aneurysm)
• An aortic valve defect (bicuspid aortic valve)
• A narrowing of the aorta at birth (aortic coarctation)

Certain genetic diseases increase the risk of having an aortic dissection, including:

Turner syndrome. High blood pressure, heart problems and other health conditions may result from this disorder.

Marfan syndrome. This is a condition in which connective tissue, which supports various structures in the body, is weak. People with this disorder often have a family history of aneurysms of the aorta and other blood vessels or family history of aortic dissections.

Other connective tissue disorders. This includes Ehlers-Danlos syndrome, a group of connective tissue disorders that involve loose joints and fragile blood vessels and Loeys-Dietz syndrome, which causes twisted arteries, especially in the neck.

Inflammation of the arteries (giant cell arteritis) may also increase your risk of aortic dissection.

Other potential risk factors for aortic dissection include:

• Sex. Men are more likely to have aortic dissection than women.
• Age. Aortic dissection is more likely in people age 60 and older.
• Cocaine use. This drug temporarily raises blood pressure.

Pregnancy. Infrequently, aortic dissections occur in otherwise healthy women during pregnancy.

High-intensity weightlifting. This and other strenuous resistance training may raise your risk of aortic dissection by increasing blood pressure during the activity.

Complications

• Possible complications of aortic dissection include:
• Death due to severe internal bleeding
• Organ damage, such as kidney failure or life-threatening intestinal damage
• Stroke
• Aortic valve damage (aortic regurgitation) or rupture into the lining around the heart (cardiac tamponade)

Prevention

You can reduce your risk of an aortic dissection by preventing chest injury and taking steps to keep your heart healthy.

Control blood pressure. If you have high blood pressure, get a home blood pressure measuring device to help you monitor your blood pressure.

Don't smoke. If you do smoke, take steps to stop.

Maintain an ideal weight. Follow a low-salt diet with plenty of fruits, vegetables and whole grains and exercise regularly.

Wear a seat belt. This reduces the risk of chest injury during a car accident.

Work with your doctor. If you have a family history of aortic dissection, a connective tissue disorder or a bicuspid aortic valve, tell your doctor. If you have an aortic aneurysm, find out how often you need monitoring and if surgery is necessary to repair your aneurysm.

If you have a genetic condition that increases your risk of aortic dissection, your doctor may recommend medications, even if your blood pressure is normal.

Diagnosis

Detecting an aortic dissection can be a challenge because the symptoms are similar to those of many other health problems. Your doctor may think you have an aortic dissection if you have:

• Sudden tearing or ripping chest pain
• Blood pressure difference between the right and left arms
• Widening of the aorta on chest X-ray

Tests to diagnose aortic dissection include:

Transesophageal echocardiogram (TEE). This test uses sound waves to create pictures of the heart in motion. A TEE is a special type of echocardiogram in which an ultrasound probe (transducer) is guided through your esophagus and placed close to your heart. This test gives your doctor a clearer picture of your heart and aorta than would a regular echocardiogram.

Computerized tomography (CT) scan of the chest. X-ray are used to produce cross-sectional images of the body. A CT of the chest can confirm a diagnosis of aortic dissection.

Magnetic resonance angiogram (MRA). An MRA uses a magnetic field and radio wave energy to create images of your blood vessels.

Treatment

An aortic dissection is a medical emergency requiring immediate treatment. Treatment may include surgery or medications, depending on the area of the aorta involved.

Type A aortic dissection

Treatment for type A aortic dissection may include:

Surgery. Surgeons remove as much of the dissected aorta as possible and stop blood from leaking into the aortic wall. A synthetic tube (graft) is used to reconstruct the aorta. If the aortic valve leaks as a result of the damaged aorta, it may be replaced at the same time. The new valve is placed within the graft.

Medications. Medications are given to reduce heart rate and lower blood pressure, which can prevent the aortic dissection from worsening. They may be given to people with type A aortic dissection to control blood pressure before surgery.

Type B aortic dissection

Treatment of type B aortic dissection may include:

Medications. The same medications that are used to treat type A aortic dissection may be used without surgery to treat type B aortic dissections.

Surgery. The procedure is similar to that used to correct a type A aortic dissection. Sometimes stents — small wire mesh tubes that act as a sort of scaffolding — may be placed in the aorta to repair complicated type B aortic dissections.

After treatment, you may need to take medication to control your blood pressure for the rest of your life. You may need regular CT scans or MRI scans to monitor your condition.