Aneurysm

What is an aneurysm?

An aneurysm is a bulging, weakened area in the wall of a blood vessel resulting in an abnormal widening or ballooning greater than 50 percent of the normal diameter (width). An aneurysm may occur in any blood vessel, but is most often seen in an artery rather than a vein.

Illustration of types of aneurysms

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An aneurysm may be located in many areas of the body, such as blood vessels of the brain, the aorta (the largest artery in the body), the intestines, the kidney, the spleen, and the vessels in the legs. The most common location of an aneurysm is the aorta, which carries oxygenated blood from the heart to the body. An aneurysm can be characterized by its location, shape, and cause.

The shape of an aneurysm is described as being fusiform or saccular, which helps to identify a true aneurysm. The more common fusiform-shaped aneurysm bulges or balloons out on all sides of the blood vessel. A saccular-shaped aneurysm bulges or balloons out only on one side.

A pseudoaneurysm, or false aneurysm, is an enlargement of only the outer layer of the blood vessel wall. A false aneurysm may be the result of a prior surgery or trauma. Sometimes, a tear can occur on the inside layer of the vessel resulting in blood filling in between the layers of the blood vessel wall creating a pseudoaneurysm.

Illustration of infrarenal abdominal aortic aneurysm

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Because an aneurysm may continue to increase in size, along with progressive weakening of the artery wall, surgical intervention may be needed. Preventing rupture of an aneurysm is one of the goals of therapy. The larger an aneurysm becomes, the greater the risk of rupture (bursting). With rupture, life-threatening hemorrhage (uncontrolled bleeding), and possibly death, may result.

What causes an aneurysm to form?

An aneurysm may be caused by multiple factors that result in the breaking down of the well-organized structural components (proteins) of the aortic wall that provide support and stabilize the wall. The exact cause is not fully known. Atherosclerosis (hardening of the arteries) is thought to play an important role in aneurysmal disease. Risk factors associated with atherosclerosis include, but are not limited to, the following:

Illustration of cerebral aneurysm

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Other specific causes of aneurysms are related to the location of the aneurysm. Examples of aneurysms in the body and their causes may include, but are not limited to, the following:

Type of Aneurysm

Causes of Aneurysms

Abdominal Aortic Aneurysm (AAA)
  • Atherosclerosis (especially in the segment of the abdominal aorta below the kidneys, called an infrarenal aortic aneurysm)
  • Genetic disorders
  • Giant cell arteritis (a disease that causes inflammation of the temporal arteries and other arteries in the head and neck, causing the arteries to narrow, reducing blood flow in the affected areas; may cause persistent headaches and vision loss)
  • Infection
Cerebral Aneurysm
  • Congenital (present at birth)
  • High blood pressure
  • Atherosclerosis
  • Head trauma
Common Iliac Artery Aneurysm
  • Atherosclerosis
  • Pregnancy
  • Infection
  • Trauma after lumbar or hip surgery
Femoral and Popliteal Artery Aneurysm
  • Atherosclerosis
  • Trauma
  • Congenital disorders

What are the symptoms of an aneurysm?

Aneurysms may be asymptomatic (no symptoms) or symptomatic (with symptoms). Symptoms associated with aneurysms depend upon the location of the aneurysm in the body.

Symptoms that may occur with different types of aneurysms may include, but are not limited to, the following:

Type of Aneurysm

Symptoms Associated with Aneurysm Type

Abdominal Aortic Aneurysm (AAA) Constant pain in abdomen, chest, lower back, or groin area
Cerebral Aneurysm sudden severe headache, nausea, vomiting, visual disturbance, loss of consciousness
Common Iliac Aneurysm Lower abdominal, back, and/or groin pain
Femoral and Popliteal Artery Aneurysm Easily palpated (felt) pulsation of the artery located in the groin area (femoral artery) or on the back of the knee (popliteal artery)

The symptoms of an aneurysm may resemble other medical conditions or problems. Always consult your physician for more information.

How are aneurysms diagnosed?

Selection of a type of diagnostic examination is related to the location of the aneurysm. In addition to a complete medical history and physical examination, diagnostic procedures for an aneurysm may include any, or a combination, of the following:

Treatment for aneurysms:

Specific treatment will be determined by your physician based on:

Treatment options for an aneurysm may include one or more of the following:

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