aortic dissection is a life-threatening condition that occurs at a rate of about 3 cases per 100,000 people per year. It involves a tearing away of the innermost lining of the aorta. It is not unlike when you put on an old winter coat, but as you slide your arm into the sleeve your fingers catch a tear in the sleeve’s lining, leading your arm into the space between the inner lining and the outer layer of the coat sleeve.

aortic dissection results when a split occurs in the wall of the aorta, the main artery that carries blood from the heart to the rest of the body. A dissection allows blood to flow between the inner and outer layers of the aortic vessel, potentially blocking blood flow to vital organs such as the brain. A dissection also places the aortic wall at increased risk for rupture, creating an acute, life-threatening condition that can only be treated by immediate surgery.

The aorta is the largest artery in the body. It starts at the heart and passes through the chest to the abdomen. Aortic aneurysms can develop anywhere along the aorta. Once an aneurysm has started to develop, it slowly expands in diameter over a period of several years. As an aneurysm grows larger, the wall of the artery thins. When the strength of the aneurysm wall becomes too weak the wall can break, resulting in a ruptured aneurysm.

There are several options for treatment of aortic aneurysms. Here again, understanding the risks and benefits of the different forms of treatment options are critical. For the remainder of the discussion we will consider aneurysms limited only to the abdomen in the most common configurations, and descending, ascending, and thoraco-abdominal aortic aneurysms will not be included.

Individuals with the following characteristics are at risk for developing Abdominal Aortic Aneurysms:

The cause of aortic dissection is still under investigation. However, there are several risk factors associated with aortic dissection, such as: bicuspid aortic valve - presence of only two cusps, or leaflets, in the aortic valve, rather than the normal three cusps polycystic kidney disease (a genetic disorder characterized by the growth of numerous cysts filled with fluid in the kidneys)

The most commonly reported symptom of an acute aortic dissection is severe, constant chest and/or upper back pain, sometimes described as "ripping" or "tearing." The pain may be "migratory," moving from one place to another, according to the direction and extent of the dissection.

In addition to a complete medical history and physical examination, diagnostic procedures for an aneurysm may include any, or a combination, of the following: computed tomography scan (Also called a CT or CAT scan.) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body.

The early mortality (death rate) is about 1% per hour, so the sooner it is diagnosed and treated, the better the outcome. Aortic dissections that involve the ascending thoracic aorta (referred to as type A) are at high risk of aortic rupture, which can be fatal, so should be taken urgently for surgery to replace the ascending portion of the aorta.

aortic aneurysm is a bulging or "ballooning" that forms in a weakened area of the aorta, the large artery that exits from the heart and carries blood to the rest of the body and to the other major arteries. An abdominal aortic aneurysm occurs in the part of the aorta in the abdomen, usually below the kidneys. Abdominal aortic aneurysms can sometimes leak or rupture, resulting in serious bleeding and possibly death.

A thoracic aortic aneurysm, also called TAA, is a bulging, weakened area in the wall of the aorta (the largest artery in the body), resulting in an abnormal widening or ballooning greater than 50 percent of the normal diameter (width). The aorta extends upward from the top of the left ventricle of the heart in the chest area (ascending thoracic aorta), then curves like a candy cane (aortic arch) downward through the chest area (descending thoracic aorta) into the abdomen (abdominal aorta).

Thoracic aortic aneurysms may be asymptomatic (without symptoms) or symptomatic (with symptoms). Symptoms of a thoracic aneurysm may be related to the location, size, and growth rate of the aneurysm. Severe onset of pain associated with a thoracic aneurysm may be a sign of a life-threatening medical emergency.

In addition to a complete medical history and physical examination, diagnostic procedures for a thoracic aortic aneurysm may include any, or a combination, of the following: computed tomography scan (Also called a CT or CAT scan.) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body.

The wall of the aorta is normally very elastic. It can stretch and then shrink back as needed to adapt to blood flow. But some medical problems, such as high blood pressure and atherosclerosis (hardening of the arteries), weaken the artery walls. These problems, along with the wear and tear that naturally occurs with aging, can result in a weak aortic wall that bulges outward.

Aneurysms are often diagnosed by chance during exams or tests done for other reasons. In some cases, they are found during a screening test for aneurysms. Screening tests help your doctor look for a certain disease or condition before any symptoms appear. Experts recommend screening tests for aneurysms for men between the ages of 65 and 75 who have ever smoked. These men are more likely to have an aneurysm than are women or nonsmoking men.

abdominal aortic aneurysm, also called AAA or triple A, is a bulging, weakened area in the wall of the aorta (the largest artery in the body) resulting in an abnormal widening or ballooning greater than 50 percent of the normal diameter (width).

No. Unfortunately abdominal aneurysms are also highly hereditary and should be detected before they can rupture.

Many patients with ascending thoracic aortic aneurysms at younger ages (30s, 40s, 50s) have Marfan syndrome or a bicuspid aortic valve as the cause. However, there are other people who have aneurysms at a young age and it appears to run in their family. A number of such families have been studied and found to have a genetic abnormality that accounts for the aortic aneurysms. This is now called a familial thoracic aortic aneurysm syndrome.

Yes. Since the early mortality (death rate) is about 1% per hour, the sooner surgery is performed, the better. Certain patients with abdominal aortic aneurysms also have blockages in the arteries to the legs, and in certain cases such blocks are repaired at the same operation to repair the abdominal aneurysm. However, if the blockages are located in the legs themselves a second procedure is most likely required to treat this.

Thoracic aortic aneurysms may be caused by different disease processes, especially in respect to their location. Examples of different locations of thoracic aortic aneurysms and their causes may include, but are not limited to, the following: cystic medial degeneration (necrosis) - breaking down of the tissue of the aortic wall. This is the most common cause of this type of thoracic aortic aneurysm.

abdominal aortic 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.

Exciting computer programs (where a student can not only take an animal apart, but also put them back together further enforcing the learning process), realistic or larger-than-life models, films, and diagrams are all effective ways to teach anatomy and physiology without harming animals. "Visifrog," a wonderful computer simulation of a frog dissection, teaches the structure and function of various organs. Students who object to dissection may call IDA at 415-388-9641 for advice or information.