Thoracic Aortic Aneurysm

The largest blood vessel in the body, the aorta delivers oxygenated blood from the heart to the rest of the body. An aortic aneurysm is a bulging, weakened area in the wall of the aorta. Aneurysms swell and weaken over time and may eventually burst (rupture) or tear (dissect), both of which can cause life-threatening bleeding and even death.

A thoracic aortic aneurysm, also called a thoracic aneurysm, forms in the section of the aorta that runs through the chest. Aneurysms that occur in the part of the aorta that runs through the belly or abdomen (abdominal aortic aneurysm) are more common than thoracic aortic aneurysms.

Thoracic aneurysms are classified according to the segment or segments of the aorta in which they occur:

1. Ascending aorta: the first segment of aorta, originating at the heart’s left ventricle and leading into the aortic arch.
2. Aortic root: the part of the ascending aorta that is closest to and attached to the heart.
3. Aortic arch: the top, arch-shaped segment of the aorta connecting the ascending aorta and the descending aorta.
4. Descending aorta: the longest part of the aorta, this segment descends from the aortic arch to carry oxygen-rich blood from the heart into the chest and diaphragm; the descending aorta becomes the abdominal aorta below the diaphragm

Most thoracic aneurysms involve the aortic root and/or the ascending aorta. Another type of thoracic aneurysm called at thoraco-abdominal aortic aneurysm (TAAA) is a bulging of both segments of the aorta (thoracic and abdominal).

What Causes Thoracic Aortic Aneurysms?

Diseases that can lead to thoracic aortic aneurysm include:

• Plaque buildup (atherosclerosis)
• Degenerative disease that causes breakdown of the aortic wall tissue
• Genetic disorders
• Family history
• Inflammation of the arteries (vasculitis)
• Uncontrolled hypertension
• Infection, though only rarely

Symptoms of Thoracic Aortic Aneurysm

Thoracic aortic aneurysms do not always cause symptoms. When symptoms are present, they can be related to the location of the aneurysm, as well the speed at which the aneurysm is growing. Sudden, severe pain connected to a thoracic aortic aneurysm may indicate a life-threatening medical emergency.

Symptoms that can accompany a thoracic aortic aneurysm include:

• Jaw, neck or upper back pain
• Chest or back pain
• Pain that resembles a heart attack
• Wheezing, coughing or shortness of breath caused by pressure on the windpipe
• Hoarse voices caused by pressure on the vocal cords or nerves leading to the vocal cords
• Trouble swallowing due to pressure on the esophagus

Symptoms of a thoracic aortic aneurysm may be similar to other conditions. Seek medical attention immediately if you suspect you have an aneurysm.

Thoracic Aortic Aneurysm Diagnosis

To diagnose a thoracic aortic aneurysm, your doctor will perform a physical exam and review your complete health and family health history. In addition, the doctor will order one or more imaging test to confirm the diagnosis. These tests include.

• Computed tomography scan (also called a CT or CAT scan)
• Magnetic resonance imaging (MRI)
• Echocardiogram (also called an echo)
• Transesophageal echocardiogram (TEE)
• Chest X-ray
• Arteriogram (also called an angiogram)

Thoracic Aortic Aneurysm Treatment

Thoracic aortic aneurysm treatment depends on the severity of the condition and if symptoms are present. Treatment options include:

• Risk Factor Management: Making some lifestyle changes may help control the progression of the aneurysm. These include quitting smoking, controlling blood sugar if you have diabetes, losing weight if overweight, controlling blood pressure and eating a healthy diet.
• Monitoring/Watchful Waiting with Imagining: MRI or CT tests are used to monitor an aneurysm’s size and growth rate.
• Medication: Your doctor may prescribe medication to control factors such as high cholesterol or high blood pressure.
• Surgery: If an aneurysm is causing symptoms or is large enough, your doctor may recommend surgery. The two main surgeries for thoracic aortic aneurysms are:
  • Thoracic aortic aneurysm open repair: The type of open surgery performed will depend on the location and type of aneurysm and the patient’s overall health. For ascending or aortic arch aneurysms, a large cut (incision) may be made through the breastbone. The surgeon then removes the damaged portion of the aorta and replaces it with a synthetic tube (graft) that is sewn into place. As part of the procedure, the aortic valve may be fixed or replaced if it is damaged. For a descending aneurysm, a larger cut may be made that extends from the back under the shoulder blade, around the side of the rib cage, to just under the breast, allowing the surgeon see the aorta directly to repair the aneurysm.
    • For large aneurysms of the aortic arch, a surgeon may recommend an aortic arch replacement, an open surgical procedure in which the aortic arch is surgically removed and replaced with a synthetic graft. As part of the procedure, the arch blood vessels (brachiocephalic, left carotid, and left subclavian arteries), which supply the brain and other organs of the upper body, are reconnected to the synthetic graft with a separate synthetic tube with three branches (trifurcation graft).
  • Thoracic endovascular aortic repair (TEVAR): This procedure only requires a small incision in the groin. Aided by X-ray guidance and special tools, the surgeon repairs the aneurysm by inserting a metal mesh coil (stent graft) into the aorta. The stent graft is expanded inside the aorta and fixed in place to make a stable channel through which blood can flow. The stent graft reinforces the weakened part of the aorta and helps to prevent rupture of the aneurysm. The TEVAR procedure is not suitable for all thoracic aneurysms.