Types of Aneurysm

Types of aneurysm include aortic aneurysms, cerebral aneurysms, and peripheral aneurysms.

Aortic Aneurysm

Most aneurysms occur in the aorta. The aorta is the main artery that carries blood from the heart to the rest of the body. The aorta comes out from the left ventricle of the heart and travels through the chest and abdomen. The two types of aortic aneurysm are thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA).

Thoracic Aortic Aneurysm

An aortic aneurysm that occurs in the part of the aorta running through the thorax (chest) is a thoracic aortic aneurysm. One in four aortic aneurysms is a TAA.

Most TAAs do not produce symptoms, even when they are large. Only half of all people with TAAs notice any symptoms. TAAs are identified more often now than in the past because of chest computed tomography (CT) scans performed for other medical problems.

In a common type of TAA, the walls of the aorta become weak and a section nearest to the heart enlarges. Then the valve between the heart and the aorta cannot close properly and blood leaks backward into the heart. Less commonly, a TAA can develop in the upper back away from the heart. A TAA in this location can result from and injury to the chest such as from an auto crash.

Abdominal Aortic Aneurysm

An aortic aneurysm that occurs in the part of the aorta running through the abdomen is an abdominal aortic aneurysm. Three in four aortic aneurysms are AAAs.

An AAA can grow very large without producing symptoms. About 1 in 5 AAAs rupture.

Figure A shows a normal aorta. Figure B shows a thoracic aortic aneurysm located behind the heart. Figure C shows an abdominal aortic aneurysm located below the arteries that supply the kidneys.

Cerebral Aneurysm

Aneurysms that occur in an artery in the brain are called cerebral aneurysms. They are sometimes called berry aneurysms because they are often the size of a small berry. Most cerebral aneurysms produce no symptoms until they become large, begin to leak blood, or rupture.

The illustration shows a typical location of a cerebral (berry) aneurysm in the arteries supplying blood to the brain. The inset image shows a closeup of the sac-like aneurysm.

A ruptured cerebral aneurysm causes a stroke. Signs and symptoms can include a sudden, extremely severe headache, nausea, vomiting, stiff neck, sudden weakness in an area of the body, sudden difficulty speaking, and even loss of consciousness, coma, or death. The danger of a cerebral aneurysm depends on its size and location in the brain, whether it leaks or ruptures, and the person’s age and overall health.

Peripheral Aneurysm

Aneurysms that occur in arteries other than the aorta (and not in the brain) are called peripheral aneurysms. Common locations for peripheral aneurysms include the artery that runs down the back of the thigh behind the knee (popliteal artery), the main artery in the groin (femoral artery), and the main artery in the neck (carotid artery).

Peripheral aneurysms are not as likely to rupture as aortic aneurysms, but blood clots can form in peripheral aneurysms. If a blood clot breaks away from the aneurysm, it can block blood flow through the artery. If a peripheral aneurysm is large, it can press on a nearby nerve or vein and cause pain, numbness, or swelling.