Thoracic Aortic Aneurysm

1 What Is Thoracic Aortic Aneurysm?

Thoracic aortic aneurysm refers to a bulging or expansion in the aorta, the largest artery in the body, in the thoracic region.

Bulging occurs when the aortic wall is weakened, and it is prone to rupture. It is also known as thoracic aneurysm and aortic dissection.

Large, rapidly growing aneurysms rupture easily when compared to small, gradually progressing aortic aneurysms.

The aneurysms can develop in any part of the aorta, which runs from the heart through the abdomen. When the aneurysm occurs in the upper part of the aorta, it is called a thoracic aortic aneurysm. However, in the thoracic region, the aneurysm can occur anywhere, including the ascending aorta, which is near the heart or the aortic arch in the curve of the thoracic aorta, and the descending aorta, which is in the lower part of the thoracic aorta.

Bleeding from a rupture of an aortic aneurysm is a potentially life-threatening condition and has to be continuously monitored.

Treatment is based on the size and growth of the aneurysm. Surgery is opted for when the risk of rupture is greater. Watchful waiting is recommended for small aneurysms. 

2 Symptoms

About 95% of thoracic aortic aneurysms are asymptomatic and thus hard to diagnose. Some bulges remain small and do not rupture, while others grow rapidly and are difficult to predict.

Growing aneurysms may push the surrounding tissue, causing symptoms like:

A sharp, severe pain in the chest indicates the rupture of the blood vessel. Pain may be felt in the jaw, neck, or arms and is often confused with heart failure. The patient may also have difficulty breathing. Aortic rupture is a serious condition that requires immediate medical attention.

Thoracic aneurysms may occur in different parts of the aorta; the bulging may be seen near the heart, in the ascending part of the blood vessel, or in the descending limb of the aorta in the thoracic region.

3 Causes

There are multiple causes for the development of thoracic aortic aneurysms. These include:

  • Atherosclerosis: Build-up of plaque in the blood vessels makes it rigid. Pressure on these blood vessels weakens the walls, causing them to bulge or expand. Hypertension and cholesterol increase the chance of developing atherosclerosis.
  • Genetic conditions: Genetic disorders like Marfan syndrome (a condition which affects the connective tissue) are linked to aortic aneurysms. This is more commonly seen in younger people, with bulging in the ascending limb of the blood vessel. Marfan syndrome is characterized by weak aortic walls that increase the risk of an aneurysm. Other disorders like Ehlers-Danlos and Loeys-Dietz syndromes are also implicated in the development of this condition.
  • Other medical conditions: Many inflammatory conditions are related to the presence of aortic aneurysms.
  • Aortic valve issues: Problems with the aortic valve increase the probability of aneurysms in the blood vessel. Having a bicuspid aortic valve, with two leaflets, is a valve condition that is a risk for developing aortic aneurysms.
  • Traumatic injury: Aortic aneurysms may develop, in some rare cases, after a traumatic injury like a fall or accident.
  • Infection left untreated: This is a rare case of thoracic aortic aneurysm, but it is possible to develop the condition if there has been an untreated infection in the body. One such example is syphilis or salmonella.

Major risk factors for thoracic aneurysms include:

  • Age: Thoracic aortic aneurysms are known to occur in adults above age sixty-five.
  • Tobacco use: Use of tobacco, cigarette smoking, or any other form of tobacco consumption increases the risk of an aortic aneurysm. Smoking or intake of tobacco leads to damage of the aorta and weakens its walls.
  • High blood pressure: High blood pressure is known to increase the damage to the blood vessels, thus increasing the chance of getting a thoracic aortic aneurysm.
  • Family medical history: Individuals who have a family history of aortic aneurysms are at an increased risk of getting this medical condition. Since there is a family history of aneurysms, they tend to develop at a very young age and are also at a higher risk of rupture.
  • Atherosclerosis, or plaque build-up in the arteries: The lining of the blood vessel can get damaged due to the build-up of fat or any other substance. This then increases the risk of developing an aneurysm. This is a common cause of concern among the elderly.
  • Marfan syndrome: If one has Marfan syndrome or any other related medical condition, such as Ehlers-Danlos syndrome, those individuals are also at a greater risk of developing a thoracic aortic aneurysm.

Many individuals suffering from a thoracic aortic aneurysm do not complain of any symptoms unless there is a tear or rupture. When a rupture occurs, it is a medical emergency, so one should not delay visiting the doctor for treatment. If the aneurysm ruptures, one or more layers of the artery wall split, which can make you feel:

  • A sudden pain shooting up the chest, neck, or arms
  • Difficulty breathing or irregular breaths
  • A sudden shooting pain in the upper back, which would start radiating downwards

4 Making a Diagnosis

Thoracic aneurysms may remain asymptomatic in many people, so they are hard to diagnose.

Rapidly developing aneurysms cause sharp chest pain. Aortic aneurysms are usually detected during routine screening or a check-up for another condition. X-ray images of the thoracic region taken for some other reason reveal aortic aneurysms.

An echocardiogram captures the images of the different parts of the aorta and the abnormalities, if any. This kind of technique is mostly used to perform screening on the family members of those individuals with a thoracic aortic aneurysm. The echocardiogram uses sound waves to capture real-time images of the heart and the ascending aorta. This technique provides details on how well the heart chambers and valves are working. In very rare cases, the doctor may recommend a transesophageal echocardiogram to better see the aorta. In this technique, sound waves are generated from within the body with the help of a device that is threaded down the individual’s esophagus.

A CT scan of the thoracic region taken after injecting a dye shows images of the different blood vessels, including the aorta. This is a painless technique that provides the doctor clear images of the aorta. This machine can also help determine the size and shape of the aneurysm. While performing the CT scan, the patient would be asked to lie down on a table that is inside a doughnut-shaped machine. The CT scan then starts generating X-rays to produce cross-sectional images of the body. If required, the doctor can also inject dye into the blood vessels to make the arteries clearer on the CT pictures. However, there are certain disadvantages with a CT scan: it causes radiation exposure, especially for people who are required to do frequent monitoring, such as those who have Marfan syndrome. There are now new techniques for CT scans that reduce the exposure to radiation, but they are not yet widely available.

MRI is another imaging technique recommended to visualize abnormalities in the thoracic blood vessels. Magnetic resonance angiography, also called MRA, is also a painless technique used to diagnose the presence or absence of an aneurysm and, at the same time, determine the exact size and location. To conduct this test, the patient has to lie down on a movable table, which then slides into a tunnel-like machine. The MRI uses a magnetic field and radio wave energy pulses to make pictures of the body. If required, doctors can inject a dye into the blood vessels to help make the blood vessels more visible on the images. For those individuals who need frequent monitoring, the MRI technique would be an alternative to the CT scan to reduce radiation exposure.

The various conditions that can cause a thoracic aneurysm may run in families, hence, the doctor can recommend certain tests be carried out to check for the presence or absence of thoracic aortic aneurysms. This is especially important if this medical condition has occurred to a first degree relative, such as a parent or sibling. Such screening tests would include imaging tests and genetic testing.

With the imaging tests, the doctor would recommend that the first degree relative should do an echocardiogram or another type of imaging test to check for Marfan syndrome or a medical condition related to thoracic aortic aneurysm. During the screening, if the doctor discovers an enlarged aorta or an aneurysm, the patient would need to do another imaging test within six months to ensure the aorta is not growing larger.

If there is a family history of Marfan syndrome or another type of genetic-related condition, it increases the risk of a thoracic aortic aneurysm. In such conditions, one may want to go to the doctor to conduct genetic testing. Before starting a family, one should also consider going for genetic counseling. 

5 Treatment

The first level of treatment for a thoracic aortic aneurysm is vessel rupture prevention.

For small aneurysms, the watch-and-wait strategy works. Regular check-ups to monitor the growth of the bulge are important as well.

Other medical conditions that worsen symptoms of an aneurysm need to be managed to prevent complications. Large, rapidly growing aneurysms require immediate attention.

Medications are given to control hypertension and high levels of cholesterol, both of which increase the risk of complications. Beta blockers, angiotensin II receptor blockers, and statins are commonly recommended medications.

Surgery is recommended when the aneurysm ranges from 1.9 to 2.4 inches or larger. Surgical treatment is also suggested if the person has a bicuspid aortic valve or a family history of aneurysms.

In open chest surgery, the aneurysm is removed and replaced with a graft. The graft has a metal mesh support that reinforces the weak walls of the blood vessel. Ruptured thoracic aortic aneurysms are repaired with emergency surgery. In endovascular surgery, the graft is placed at the site of the aneurysm using a catheter inserted through the artery.

6 Prevention

Controlling risk factors is the best preventive measure for a thoracic aortic aneurysm. Healthy diet and regular exercise help to avoid atherosclerosis, one of the risk factors of an aneurysm.

The risk of aneurysms can be reduced by:

Regular check-ups are a must if there is a family history of aneurysms.

7 Alternative and Homeopathic Remedies

A few alternative and homeopathic remedies exist for thoracic aortic aneurysms.

In homeopathy, veratrum viride is used to control pulse rate.

Other medications used include:

  • Gallicum acidum
  • Ergotinum
  • Baryta muriatica
  • Aconite
  • Digitalis
  • Gelsemium
  • Laurocerasus

Garlic is suggested for controlling hypertension and reducing the risk of heart disease

8 Lifestyle and Coping

Lifestyle modifications are necessary in order to cope with a thoracic aortic aneurysm.

One should avoid stressful situations and strenuous, physical activity, both of which increase the pressure on aneurysms.

Taking healthy steps like quitting smoking, managing blood pressure, and reducing cholesterol in the diet help reduce the risk of developing aneurysms.

Talking to an expert and being a part of a support group help to cope with the condition. 

9 Risks and Complications

The main complication of a thoracic aortic aneurysm is the rupture of the blood vessel. This may lead to:

  • Sudden shooting pain in the chest
  • Low blood pressure
  • Loss of consciousness
  • Difficulty breathing
  • Trouble swallowing
  • Paralysis on one side of the body

Risk of blood clots also increases with aortic aneurysms. One of the major complications of an aortic aneurysm is a blood clot. Small blood clots can develop in the region of the aortic aneurysm. If this blood clot breaks from inside the wall of the aneurysm, it can create a blockage at the blood vessel in some other part of the body, which could then lead to other serious complications and, in the worst-case scenario, death.

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