The aorta is the main artery that carries blood from the heart to the rest of the body. It is shaped like a candy cane and is typically about as wide as a garden hose (2.5‐3.5 cm in diameter). When blood is pumped out by the heart, it first travels through the ascending thoracic aorta (up the short arm of the candy cane), then down the descending thoracic aorta (first part of the long arm) into the abdominal aorta (the bottom of the candy cane).
An aortic aneurysm is a widening, bulge, or ballooning of a portion of the aorta. Aneurysms can involve any part of the aorta where there is a weakness in the aortic wall, but most commonly they occur either in the segment of the aorta where it comes out of the heart (an ascending thoracic aortic aneurysm) or in the abdominal aorta above the pelvic area (an abdominal aortic aneurysm). If an ascending thoracic aortic aneurysm is not treated, it will enlarge over time without any symptoms. If the aneurysm is not surgically repaired, it can cause a life‐threatening event, such as an acute aortic dissection or rupture. Aortic aneurysms are the 13th leading cause of death in the United States, accounting for an estimated 15,000 deaths annually.
Kuivaniemi H, Platsoucas CD, Tilson D. Aortic aneurysms: an immune disease with a strong genetic component. Circulation. 2008;117:242-252.
An aortic dissection is a life‐threatening event that occurs when there is a tear in the wall of the aorta that allows blood to flow within the wall of the aorta. It causes an increasing weakness, or bulging, of the wall of the aorta. The dissection makes the aorta unstable, and it can rupture or dissect into areas of the body where it can cause life‐threatening problems. When the wall of the aorta tears open completely, it can result in massive bleeding. This can also cause blockages of major branch arteries supplying blood to the heart, brain, intestines, liver, kidneys, or legs.
Approximately 40% of individuals with dissection involving the ascending aorta die suddenly and do not make it to the hospital. If they do make it to the hospital, the dissection needs to be diagnosed quickly and emergency surgery needs to be performed to repair the dissection. Fifty percent of patients with undiagnosed aortic dissection die within 48 hours.
Early diagnosis and treatment is critical for survival because the chances of successful surgical repair are very good in a stable situation. A delay in diagnosis and treatment can result in severe complications, and even death.
Aortic dissections have ranked as high as the 15th leading cause of death in the United States, accounting for an estimated 15,000 deaths annually. Although dissections are more common in people over the age of 50, they can occur at any age. Most of these deaths are preventable if individuals at risk are identified and the aortic disease properly managed.
Many people who suffer an aortic dissection have an aneurysm prior to the dissection, and these aneurysms can be treated medically and surgically to prevent the aortic dissections. Early diagnosis by imaging and treatment of an aneurysm is critical for survival because surgical repair of the ascending thoracic aortic aneurysm prevents the aortic dissection. This surgery is done routinely with very few associated complications. In addition, physicians can monitor and treat an aneurysm with medications to slow the growth of the aorta prior to surgery.
Thoracic aortic aneurysms (TAAs) may involve the ascending aorta, the arch, or the descending aorta in the chest. The predisposition for a TAA may be genetic and can occur at any age or it may be degenerative, related to aging or uncontrolled high blood pressure. Growth of the aneurysm can be relatively fast. Thoracic aortic aneurysms tend to rupture or dissect the larger they grow.
Abdominal aortic aneurysms (AAA) affect the aorta in the abdominal cavity where it feeds abdominal organs and the lower body. Abdominal aortic aneurysms tend to affect men over the age of 60 and can take longer to develop. Abdominal aortic aneurysms tend to rupture the larger they grow.
Physicians can monitor and treat an aneurysm with medications to slow the growth and reduce the risk of enlargement or dissection. Adequately treating high blood pressure can reduce the risk of enlargement or dissection as well.