An abnormal widening or ballooning of a portion of a blood vessel. The blood vessel wall becomes weaker in this location. Aneurysms can occur in any artery in the body. Some common locations for aneurysms include:

Causes, incidence, and risk factors

Aneurysms are either congenital or acquired. It is not clear exactly what causes aneurysms. In certain cases (abdominal aortic aneurysms), hypertension is thought to be a contributing factor. Atherosclerotic disease (cholesterol buildup in arteries) may contribute to the formation of certain types of aneurysms. Pregnancy is often associated with the formation and/or rupture of splenic artery aneurysms.

Signs and tests

Physical exam, ultrasound examination, and CT scan are used to evaluate aneurysms.

Treatment

Surgical excision is generally recommended. The timing and indications for surgery differ depending on the type of aneurysm.

Expectations (prognosis)

With successful surgical repair, the prognosis is excellent.

Complications

The main complications of aneurysm include rupture, infection and compression of local structures. Rupture of the aneurysm, with massive bleeding, which is often fatal-this is seen with abdominal aortic aneurysms, mesenteric artery aneurysms, and splenic artery aneurysms. Infection of the aneurysm, which sometimes follows infection at other sites of the body, can lead to systemic illness and rupture. Thrombosis of the aneurysm occurs when blood clots inside the aneurysm, blocking further blood flow past the site of the aneurysm and depriving tissues of blood supply. In certain cases, aneurysms can compress neighboring structures such as nerves, leading to neurologic deficits such as weakness and numbness. This can occur with popliteal artery aneurysms.

Calling your health care provider

Call your physician for any new mass, whether or not it is pulsatile.

Prevention

Control of high blood pressure may help prevent some aneurysms. Control of all risk factors associated with atherosclerotic disease (diet exercise, cholesterol control) may help prevent aneurysms or their complications.