What are aneurysms? |

Causes and Symptoms

The arterial distension associated with aneurysms will take one of several forms. For example, fusiform aneurysms create a uniform bulge around an artery, while those of the saccular variety distend on one side of the blood vessel. Some saccular aneurysms found in the brain are called berry aneurysms for their protruding shapes.

Hypertension and arteriosclerosis
commonly produce dilatation of the thoracic aorta. Very large aneurysms of the abdominal aorta (possibly the most common type) are usually caused by advanced atherosclerosis. The pathologic processes associated with the production of aortic aneurysms are varied, but certain factors are common to all. The media (middle arterial layer) of the normal aorta must remain intact in order for the aorta to withstand the systolic blood pressure. When the media is damaged, there is progressive dilation of the weakened area and an aneurysm develops. An aortic aneurysm is a serious disease with poor prognosis. Many such aneurysms rupture and cause death before surgical intervention can take place.

There are several types of aneurysms. Dissecting aortic aneurysms are those in which blood enters the wall of the blood vessel and splits the media of the vessel. The dissection of the media usually begins as a transverse tear in the region above the aortic valve and works downward between the layers of the aortic wall. Some believe that hypertension promotes the tear by increasing the tension on the aorta. Traumatic aneurysm is usually caused by penetrating wounds or by blunt trauma; the most common cause of such injuries is automobile accidents. Mycotic aneurysms of the aorta may be associated with bacterial endocarditis and sometimes with organisms such as salmonella. Aneurysms of the sinuses of Valsalva may be attributable to syphilitic aortitis, bacterial endocarditis, or congenital defect.

Treatment and Therapy

Surgical therapy for thoracic aortic aneurysms varies with the type and location of the lesion. Aneurysms involving the aortic arch are often surgically corrected by employing a bypass technique. One method sutures a large prosthetic graft between the ascending and descending aortas, thus bypassing the diseased area. Surgical techniques sometimes offer the only hope for the survival of a patient with aneurysm. A 2013 study identified that small aneurysms grow more slowly than larger aneurysms. It suggested that diagnostic imaging of patients with small aneurysms can occur with less frequency, increasing the cost effectiveness of treatment.

Bibliography

Adelman, Mark. "News release."  Journal of the American Medical Association. (2013): Web. 22 May. 2013.

Goldman, Lee, and Dennis Ausiello, eds. Cecil Textbook of Medicine. 23d ed. Philadelphia: Saunders/Elsevier, 2007.

Keen, Richard R., and Philip B. Dobrin, eds. Development of Aneurysms. Georgetown, Tex.: Landes Bioscience, 2000.

Parker, James N., and Philip M. Parker, eds. The Official Patient’s Sourcebook on Cerebral Aneurysm. San Diego, Calif.: Icon Health, 2002.

Yao, James S. T., and William H. Pearce, eds. Aneurysms: New Findings and Treatments. Norwalk, Conn.: Appleton & Lange, 1994.