Aortic Aneurysm

Causes

A major cause of aortic aneurysm is the breakdown of the muscular layer and the elastic fibers of the aorta caused by atherosclerosis (hardening of the arteries) or, more commonly, high blood pressure and tobacco abuse. As the tissues break down, the wall weakens and the pressure within the aorta causes the wall to stretch. As the aorta enlarges, it forms an aneurysm.

Inherited conditions such as Marfan syndrome, which results in a weakness of the aorta, may cause aortic aneurysm.

Mycotic aneurysms are caused by infections of the aorta.

Post-traumatic pseudoaneurysms occur after sudden deceleration injuries such as those caused by a car accident. When the aorta wall is torn, an aneurysm forms suddenly. Pseudoaneurysms also may occur as a consequence of atherosclerosis when hardened fatty deposits penetrate the aortic wall.

Risk Factors

Age, hypertension (high blood pressure) and smoking are the principal risk factors for aneurysm. The majority of patients with aortic dissections have a history of high blood pressure that often has not been well controlled.

A tendency toward abdominal aneurysms and thoracic aneurysms can run in families. It is important to inform the physician if other family members have had aneurysms.

Prevention

The best way for patients to prevent an aneurysm is to control blood pressure and not smoke.

Medications that slow the heart rate, such as beta-blockers, may help prevent aneurysm formation and expansion. At Mayo Clinic, researchers are studying the use of tetracyclines to inhibit the growth of small aneurysms.

The most important aspect of care is to identify aneurysms early and then monitor them closely.