Aortic aneurysm overview
Synonyms and keywords:

# Overview
An aortic aneurysm is a dilation of the aorta representing an underlying weakness in the wall of the aorta at that location. While the stretched vessel may occasionally cause discomfort, a greater concern is the risk of rupture which causes severe pain, massive internal hemorrhage which are often fatal.

# Historical Perspective
Aortic aneurysm was first discovered by Antyllus, a a Greek surgeon, in the second century AD.
In 1817, a ligation of the abdominal aorta was used by Astley Cooper to treat a ruptured iliac aneurysm.

# Classification
Aortic aneurysm may be classified according to Crawford classification into 5 types: type 1, type 2, type 3, type 4 and type 5.

# Pathophysiology
It is thought that aortic aneurysm is the result of either genetic disturbances and environmental risks such as smoking.

# Causes
Aortic aneurysm may be caused by Marfan's syndrome, Loeys-Dietz syndrome, Ehler-Danlos syndrome, Turner Syndrome, Autosomal Dominant Polycystic Kidney Disease and other genetic disturbances.
Its risk is greatly improved with smoking.

# Differentiating aortic aneurysm from other Diseases
Aortic aneurysms must be differentiated from other diseases that cause either abdominal or thoracic pain, such as acute pancreatitis, ruptured viscus, and acute pericarditis.

# Epidemiology and Demographics
The incidence of aortic aneurysm increases with age; the median age at diagnosis is 69 years.

# Risk Factors
Common risk factors in the development of aortic aneurysms include smoking, male gender, hypertension, race (whites) and family history.

# Screening
According to the USPSTF, screening for abdominal aortic aneurysm by ultrasonography is recommended once among patients aged 65 to 75 years who have ever smoked.

# Natural History, Complications, and Prognosis
If left untreated, 80% of patients with aortic aneurysms may progress to rupture or dissection.

# Diagnosis

## Diagnostic Study of Choice
The diagnosis of aortic aneurysm is based on the observed diameter of the vessel, which include diameter larger than 5 cm for the ascending aorta, 4 cm for the descending aorta, and 3cm for the abdominal aorta.

## History and Symptoms
The majority of patients with aortic aneurysm are asymptomatic.

## Physical Examination
Patients with aortic aneurysm usually appear asymptomatic. Physical examination of patients with abdominal aortic aneurysm is usually remarkable for pulsating abdominal mass. If thoracic they may present with hoarseness, dysphagia and aortic regurgitation.

## Laboratory Findings
There are no diagnostic laboratory findings associated with aortic aneurysm.

## Electrocardiogram
There are no ECG findings associated with aortic aneurysm.

## X-ray
An x-ray may be helpful in the diagnosis of thoracic aortic aneurysm. Findings on an x-ray suggestive of thoracic aortic aneurysm include widening of the mediastinum.

## Echocardiography or Ultrasound
Abdominal ultrasound may be helpful in the diagnosis of abdominal aortic aneurysm. Findings on an ultrasound diagnostic of abdominal aortic aneurysm include aorta with a diameter larger than 3 cm.

## CT scan
Thoracic or abdominal CT scan may be helpful in the diagnosis of aortic aneurysms. Findings on CT scan diagnostic of aortic aneurysms include widening of the aorta diameter.

## MRI
Thoracic or abdominal MRI may be helpful in the diagnosis of aortic aneurysms. Findings on MRI diagnostic of aortic aneurysms include widening of the aorta diameter.

## Other Imaging Findings
Angiographies may be helpful in the diagnosis of aortic aneurysms. Findings on an angiography diagnostic of aortic aneurysms include widening of the aorta diameter.

## Other Diagnostic Studies
There are no other diagnostic studies associated with aortic aneurysm.

# Treatment

## Medical Therapy
Pharmacologic medical therapies for aortic aneurysms include blood pressure control and statin therapy if associated with atherosclerosis.

## Surgery
The mainstay of treatment for aortic aneurysms is medical therapy. Surgery is usually reserved for patients with an abdominal aortic aneurysm larger than 5.5 cm. For thoracic aortic aneurysms, it is reserved for patients with symptoms, aneurysm that is growing more than 1 centimeter per year and/or signs of aortic dissection.

## Primary Prevention
Effective measures for the primary prevention of aortic aneurysms include avoid smoking and controlling blood pressure.

## Secondary Prevention
Effective measures for the secondary prevention of aortic aneurysms include ultrasound screening as described above.