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Thoracic aortic aneurysm
Definition
An aneurysm is an abnormal widening or ballooning of a portion of an artery due to weakness in the wall of the blood vessel.
A thoracic aortic aneurysm occurs in the part of the body's largest artery (the aorta) that passes through the chest.
Alternative Names
Aortic aneurysm - thoracic; Syphilitic aneurysm; Aneurysm - thoracic aortic
Causes
The most common cause of a thoracic aortic aneurysm is hardening of the arteries (atherosclerosis). This condition is more common in people with high cholesterol, long-term high blood pressure, or who smoke.
Other risk factors for a thoracic aneurysm include:
- Changes caused by age
- Connective tissue disorders such as Marfan syndrome
- Inflammation of the aorta
- Injury from falls or motor vehicle accidents
- Syphilis
Symptoms
Aneurysms develop slowly over many years. Most patients have no symptoms until the aneurysm begins to leak or expand. The aneurysm may be found only when imaging tests are done for other reasons.
Symptoms often begin suddenly when:
- The aneurysm grows quickly
- The aneurysm tears open (called a rupture)
- Blood leaks along the wall of the aorta (aortic dissection)
If the aneurysm presses on nearby structures, the following symptoms may occur:
- Hoarseness
- Swallowing problems
- High-pitched breathing (stridor)
- Swelling in the neck
Other symptoms may include:
- Chest or upper back pain
- Clammy skin
- Nausea and vomiting
- Rapid heart rate
- Sense of impending doom
Exams and Tests
The physical examination is often normal unless a rupture or leak has occurred.
Most thoracic aortic aneurysms are detected by tests performed for other reasons, usually a chest x-ray, echocardiogram, or a chest CT scan or MRI. A chest CT scan shows the size of the aorta and the exact location of the aneurysm.
An aortogram (a special set of x-ray images made when dye is injected into the aorta) can identify the aneurysm and any branches of the aorta that may be involved.
Treatment
There is a risk that the aneurysm may open up (rupture) if you do not have surgery to repair it.
The treatment depends on the location of the aneurysm. The aorta is made of three parts:
- The first part moves upward towards the head. It is called the ascending aorta.
- The middle part is curved. It is called the aortic arch.
- The last part moves downward, toward the feet. It is called the descending aorta.
For patients with aneurysms of the ascending aorta or aortic arch:
- Surgery to replace the aorta is recommended if an aneurysm is larger than 5 - 6 centimeters.
- A cut is made in the middle of the chest bone.
- The aorta is replaced with a plastic or fabric graft.
- This is major surgery that requires a heart-lung machine.
For patients with aneurysms of the descending thoracic aorta:
- Majory surgery is done to replace the aorta with a fabric graft if the aneurysm is larger than 6 centimeters.
- This surgery is done through a cut on the left side of the chest, which may reach to the abdomen.
- Endovascular stenting is a less invasive option. A stent is a tiny metal or plastic tube that is used to hold an artery open. Stents can be placed into the body without cutting the chest. Not all patients with descending thoracic aneurysms are candidates for stenting, however.
Outlook (Prognosis)
The long-term outlook for patients with thoracic aortic aneurysm depends on other medical problems, such as heart disease, high blood pressure, and diabetes, which may have caused or contributed to the condition.
Possible Complications
Serious complications after aortic surgery can include:
- Bleeding
- Graft infection
- Heart attack
- Irregular heartbeat
- Kidney damage
- Paralysis
- Stroke
Death soon after the operation occurs in 5 - 10% of patients.
Complications after aneurysm stenting include damage to the blood vessels supplying the leg, which may require another operation.
When to Contact a Medical Professional
Tell your doctor if you have:
- A family history of connective tissue disorders (such as Marfan syndrome)
- Chest or back discomfort
Prevention
To prevent atherosclerosis:
- Control your blood pressure and blood lipid levels.
- Do not smoke.
- Eat a healthy diet.
- Exercise regularly.
References
Tracci MC, Cherry KJ. The aorta. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL. Sabiston Textbook of Surgery. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2012:chap 62.
Cheng D, Martin J, Shennib H, et al. Endovascular aortic repair versus open surgical repair for descending thoracic aortic disease: a systematic review and meta-analysis of comparative studies. J Am Coll Cardiol. 2010:55(10):986-1001.
Isselbacher EM. Diseases of the aorta. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 78.
Reviewed By: Shabir Bhimji MD, PhD, Specializing in Cardiothoracic and Vascular Surgery, Midland , TX. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.
