What is Thoracic Aortic Aneurysm?
An aneurysm is a localized dilation or a bulge in the blood vessel due to weakening of the vessel wall. Aneurysm occurring in the weakened area of the upper part of the aorta is known as thoracic aortic aneurysm. The aorta is a vital blood vessel which provides oxygenated blood to the body. A thoracic aortic aneurysm can also be termed as Thoracic Aneurysm and Aortic Dissection (TAAD), as aneurysm can also lead to a dissection, which means a tear in the artery wall, resulting in life-threatening bleeding. Thoracic aortic aneurysms which are small and slow-growing may not ever rupture, but the larger and faster-growing aneurysms are at a risk for rupture and bleeding.
Aneurysms can develop anywhere in the aorta. If the aneurysm is formed in the upper part of the aorta, they are known as thoracic aortic aneurysms. Aneurysms commonly develop in the lower part of the aorta and are known as abdominal aortic aneurysms. Aneurysms developing in between the upper and lower parts of the aorta are known as thoracoabdominal aneurysm and this type of aneurysm is rare.
Treatment depends on the size and growth rate of the thoracic aortic aneurysm. Treatment can vary from watchful waiting to emergency surgery.
Causes and Risk Factors of Thoracic Aortic Aneurysm or Thoracic Aneurysm and Aortic Dissection (TAAD)
The exact cause of thoracic aortic aneurysm is not known, but contributing factors to the development of an aneurysm include:
- Atherosclerosis: This is a condition where the arteries get harden due to building up of plaque in the artery walls. This decreases the flexibility of the arteries and further pressure on them causes weakening and bulging of the artery walls. High blood pressure and high cholesterol are the common risk factors for atherosclerosis.
- Connective Tissue Disorders: Individuals who are born with Marfan syndrome, which is a genetic condition affecting the connective tissue, are at a higher risk for thoracic aortic aneurysm. Other than Marfan syndrome, other connective tissue diseases include Ehlers-Danlos and Loeys-Dietz.
- Other Medical Conditions: Inflammatory conditions like giant cell arteritis and Takayasu's arteritis may also increase the risk of thoracic aortic aneurysm.
- Problems with Heart Valves: Individuals with aortic valve problems, such as bicuspid aortic valve, are at an increased risk of thoracic aortic aneurysm.
- Infections Which are Left Untreated: Such infections may not be the common cause of thoracic aortic aneurysm, but it increases the chances for thoracic aortic aneurysm, especially infections such as syphilis or salmonella.
- Trauma or Injury: Individuals who get injured in falls or motor vehicle accidents tend to develop thoracic aortic aneurysms.
Risk Factors of Thoracic Aortic Aneurysm or Thoracic Aneurysm and Aortic Dissection (TAAD)
- Individuals aged 65 and above are at increased risk for developing thoracic aortic aneurysms.
- Individuals using tobacco are at higher risk for the development of an aortic aneurysm.
- Hypertension (high blood pressure) damages the blood vessels and increases the chances of developing an aneurysm.
- Atherosclerosis, which is hardening of arteries due to buildup of plaques, damages the lining of the blood vessel and increases the risk of an aneurysm.
- People with family history of aortic aneurysm are at increased risk of having one and these individuals also tend to develop aneurysms at a younger age and are at increased risk of rupture.
- Individuals with connective tissue disorders (Marfan syndrome, Ehlers-Danlos syndrome) are at a significantly higher risk for developing thoracic aortic aneurysm.
Signs and Symptoms of Thoracic Aortic Aneurysm or Thoracic Aneurysm and Aortic Dissection (TAAD)
Thoracic aortic aneurysm usually grows slowly and often without symptoms and this makes it difficult to detect. There are some aneurysms which will never rupture. Many of them start small and stay small and some increase in size gradually. The growth rate of an aneurysm is difficult to predict.
Some of the Symptoms of Thoracic Aortic Aneurysm or Thoracic Aneurysm and Aortic Dissection (TAAD) Include:
- Pain or tenderness in the chest.
- Pain in the back.
- Shortness of breath.
Serious Symptoms Indicating Rupture of Aneurysm Include:
- Sudden, sharp pain in the upper back which radiates downwards.
- Pain in the chest, jaw, neck or arms.
- Breathing difficulties.
Tests to Diagnose Thoracic Aortic Aneurysm or Thoracic Aneurysm and Aortic Dissection (TAAD)
Thoracic aortic aneurysms are usually detected during routine medical exams, such as a chest X-ray or ultrasound of the heart or abdomen. Tests or procedures to confirm an aneurysm include:
- Chest X-ray.
- Computerized tomography or (CT) scan.
- Magnetic resonance angiography (MRA).
- Screening tests for those conditions which cause thoracic aortic aneurysm to run in families include imaging tests such as echocardiogram.
- Genetic testing for patients having a family history of Marfan syndrome, or other genetic conditions which increase the risk of thoracic aortic aneurysm.
Treatment for Thoracic Aortic Aneurysm or Thoracic Aneurysm and Aortic Dissection (TAAD)
The main aim of treatment is to prevent the aneurysm from rupturing. Generally, the treatment comprises of medical monitoring or surgery. The decision of which to follow depends on the size and the rate of growth of the aortic aneurysm.
- Medical Monitoring: If the thoracic aortic aneurysm is small, then medical monitoring may be recommended. This includes regular appointments to ensure that the aneurysm isn't growing, along with management of other medical conditions which could lead to worsening of the aneurysm. Medical monitoring comprises of regular imaging tests to check the size of the aneurysm, such as an echocardiogram at least six months after the diagnosis of aneurysm with regular exams and imaging tests following that.
- If the patient has hypertension (high blood pressure) or blockages in arteries, then the doctor will prescribe medications to lower the blood pressure and cholesterol levels, so that the risk of complications from the aneurysm are significantly decreased. These medications include:
- Beta blockers such as metoprolol (Lopressor, Toprol-XL), atenolol (Tenormin) and bisoprolol (Zebeta).
- Angiotensin II receptor blockers are prescribed if beta blockers aren't sufficient to control blood pressure or if the patient can't take beta blockers for some reasons. These medications are also recommended for patients having Marfan syndrome, even if they aren't suffering from hypertension. Angiotensin II receptor blockers include losartan (Cozaar), valsartan (Diovan) and olmesartan (Benicar).
- Statins are given to help lower cholesterol, which in turn helps in cutting down the blockages in arteries and reducing the risk of complications from aneurysm. Statins include atorvastatin (Lipitor), lovastatin (Mevacor) and simvastatin (Zocor).
- If the patient smokes or chews tobacco, then it is important that the patient quit smoking or chewing tobacco, as it can worsen the aneurysm.
- Surgery: Surgery is usually recommended if the size of aneurysm is large, i.e. if it is about 1.9 to 2.4 inches (5 to 6 centimeters) or larger. Surgery is done to prevent rupture of the aneurysm. If the patient has Marfan syndrome or any other connective tissue disease or a family history of aortic dissection, then surgery is even recommended for smaller aneurysms, as there is a high risk of having an aortic dissection. The type of surgery done depends on patient's general condition and the location of the thoracic aortic aneurysm.
- Open Chest Surgery: This involves replacing the damaged section of the aorta with a synthetic tube (graft), which is sewn into place. This surgical procedure comprises of open abdominal or open chest surgery. It usually takes one month or more to fully recover from the surgery.
- Endovascular Surgery: In this type of surgery, a synthetic graft is attached to the end of a catheter (thin tube) which is inserted through an artery in the leg and eased up into the aorta. The graft is a woven tube which is covered by a metal mesh support. This graft is placed at the site of the aneurysm and is fixed in place using small hooks or pins. This graft helps in reinforcing the weakened section of the aorta which helps in preventing rupture of the aneurysm. In this type of surgery, the recovery time is faster than open surgery, but endovascular surgery is not recommended for everyone. After endovascular surgery is done, patient needs regular follow-up imaging scans to make sure that the graft isn't leaking.
- Other Surgeries for Heart: If there are other medical conditions which are contributing to development of the aneurysm, such as problem with the heart's valves (bicuspid valve), then other additional surgeries to repair or replace the damaged valves are recommended to prevent worsening of the aneurysm.
- Emergency Surgery: Although emergency surgery can be done on patients, the risk is greater in emergency surgery and the chances of survival are less.
Lifestyle and Home Remedies for Thoracic Aortic Aneurysm or Thoracic Aneurysm and Aortic Dissection (TAAD)
- Patient should avoid heavy lifting and vigorous physical activities.
- Patient should avoid stress and try to stay calm by doing meditation.
- Patient should quit using tobacco products.
- Always try to keep blood pressure under control.
- Do regular exercises daily.
- Make dietary changes by reducing cholesterol and fat intake.