A thoracic aortic aneurysm is an
aortic aneurysm
An aortic aneurysm is an enlargement (dilatation) of the aorta to greater than 1.5 times normal size. They usually cause no symptoms except when ruptured. Occasionally, there may be abdominal, back, or leg pain. The prevalence of abdominal aortic ...
that presents primarily in the
thorax
The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...
.
A thoracic aortic aneurysm is the "ballooning" of the upper aspect of the aorta, above the diaphragm. Untreated or unrecognized they can be fatal due to dissection or "popping" of the aneurysm leading to nearly instant death. Thoracic aneurysms are less common than an
abdominal aortic aneurysm
Abdominal aortic aneurysm (AAA) is a localized enlargement of the abdominal aorta such that the diameter is greater than 3 cm or more than 50% larger than normal. They usually cause no symptoms, except during rupture. Occasionally, abdominal, ...
. However, a
syphilitic aneurysm is more likely to be a thoracic aortic aneurysm than an abdominal aortic aneurysm. This condition is commonly treated via a specialized multidisciplinary approach with both
vascular surgeons
Vascular surgery is a surgical subspecialty in which diseases of the vascular system, or arteries, veins and lymphatic circulation, are managed by medical therapy, minimally-invasive catheter procedures and surgical reconstruction. The specialty ...
and
cardiac surgeons
Cardiothoracic surgery is the field of medicine involved in surgical treatment of organs inside the thoracic cavity — generally treatment of conditions of the heart ( heart disease), lungs (lung disease), and other pleural or mediastinal st ...
.
Presentation
![AneurysmT](https://upload.wikimedia.org/wikipedia/commons/a/ac/AneurysmT.PNG)
Complications
The principal causes of death due to thoracic aneurysmal disease are
dissection
Dissection (from Latin ' "to cut to pieces"; also called anatomization) is the dismembering of the body of a deceased animal or plant to study its anatomical structure. Autopsy is used in pathology and forensic medicine to determine the cause o ...
and
rupture
Rupture may refer to:
General
* Rupture (engineering), a failure of tough ductile materials loaded in tension
Anatomy and medicine
* Abdominal hernia, formerly referred to as "a rupture"
* Achilles tendon rupture
* Rupture of membranes, a "wate ...
. Once rupture occurs, the mortality rate is 50–80%. Most deaths in patients with
Marfan syndrome
Marfan syndrome (MFS) is a multi-systemic genetic disorder that affects the connective tissue. Those with the condition tend to be tall and thin, with long arms, legs, fingers, and toes. They also typically have exceptionally flexible joints a ...
are the result of aortic disease.
Causes
There are a number of causes, Aneurysms in patients younger than 40 usually involve the ascending aorta due to a weakening of the aortic wall associated with connective tissue disorders like the
Marfan and
Ehler-Danlos syndromes or congenital bicuspid aortic valve. Younger patients may develop aortic aneurysms of the thoracoabdominal aorta after an aortic dissection. It can also be caused by blunt injury. Atherosclerosis is the principal cause of descending aortic aneurysms, while aneurysms of the aortic arch may be due to dissection, atherosclerosis, or inflammation.
Age
The diagnosis of thoracic aortic aneurysm usually involves patients in their 60s and 70s.
Risk factors
Hypertension and cigarette smoking are the most important risk factors, though the importance of genetic factors has been increasingly recognized. Approximately 10 percent of patients may have other family members who have aortic aneurysms. It is also important to note that individuals with a history of aneurysms in other parts of the body have a higher chance of developing a thoracic aortic aneurysm.
Diagnosis
![Aorta segments](https://upload.wikimedia.org/wikipedia/commons/5/5c/Aorta_segments.svg)
Thoracic aortic aneurysm is defined as a cross-sectional diameter exceeding the following
cutoff:
* 4.5 cm in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
[
* 4.0 cm in ]South Korea
South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...
A diameter of 3.5 cm is generally considered dilated. However, average values vary with age and size of the reference population, as well as different segments of the aorta.
Screening
Guidelines were issued in March 2010 for early detection of thoracic aortic disease, by the American College of Cardiology, the American Heart Association, and other groups. Among the recommendations:
* First-degree relatives of people with thoracic aortic aneurysm or dissection should have aortic imaging to identify asymptomatic disease.
* People with symptoms suggestive of thoracic aortic dissection should be routinely evaluated "to establish a pretest risk of disease that can then be used to guide diagnostic decisions."
* People diagnosed with Marfan syndrome should immediately have an echocardiogram to measure the aorta and followed up six months later to check for aortic enlargement.
Treatment
The size cut off for aortic aneurysm is crucial to its treatment. A thoracic aorta greater than 4.5 cm is generally defined as aneurysmal, while a size greater than 6 cm is the distinction for treatment, which can be either endovascular or surgical, with the former reserved for pathology at the descending aorta.
Indication for surgery may depend upon the size of the aneurysm. Aneurysms in the ascending aorta may require surgery at a smaller size than aneurysms in the descending aorta
In human anatomy, the descending aorta is part of the aorta, the largest artery in the body. The descending aorta begins at the aortic arch and runs down through the chest and abdomen. The descending aorta anatomically consists of two portions o ...
.
Treatment may be via open
Open or OPEN may refer to:
Music
* Open (band), Australian pop/rock band
* The Open (band), English indie rock band
* ''Open'' (Blues Image album), 1969
* ''Open'' (Gotthard album), 1999
* ''Open'' (Cowboy Junkies album), 2001
* ''Open'' (YF ...
or via endovascular
Interventional radiology (IR) is a medical specialty that performs various minimally-invasive procedures using medical imaging guidance, such as x-ray fluoroscopy, computed tomography, magnetic resonance imaging, or ultrasound. IR performs b ...
means.
Epidemiology
Each year in the United States, some 45,000 people die from diseases of the aorta and its branches. Acute aortic dissection, a life-threatening event due to a tear in the aortic wall, affects 5 to 10 patients per million population each year, most often men between the ages of 50 and 70; of those that occur in women younger than 40, nearly half arise during pregnancy. The majority of these deaths occur as a result of complications of thoracic aneurysmal disease
References
External links
{{Vascular diseases
Diseases of the aorta
Vascular diseases