A type of aneurysm, an aortic aneurysm is an abnormal enlargement in the wall of the aorta, which is the body's largest artery and is tasked with carrying blood from the heart to the rest of the body. Small aneurysms often pose no threat to human health, but larger aneurysms can lead to a series of serious medical problems including plaque formation, blood clots, and total rupture.
Definition & Facts
Aneurysms involve the emergence of weak spots in artery walls, which allows pressure from inside the artery to cause a bulge in two or even three walls of the artery. There are two main types of aortic aneurysms: abdominal aortic aneurysms and thoracic aortic aneurysms. Abdominal aortic aneurysms occur in the part of the aorta that passes through the lower abdomen, while thoracic aortic aneurysms occur in the part of the aorta that passes through the chest cavity.
Segments of the aorta that pass through the chest cavity include the aortic root, the ascending aorta, the aortic arch, and the descending aorta. Although the vast majority of aneurysms occur in the aorta or the brain, they can occur in any blood vessel of the circulatory system including those that travel to or through the knee, the kidney, or other internal organs.
Symptoms & Complaints
Many symptoms come as the result of increased pressure on internal organs, such as the lungs, stomach, or esophagus. If an aneurysm ruptures, there will be extreme and obvious physical symptoms, including stroke, heart attack, or loss of consciousness.
In general, symptoms include extreme pain between the shoulder blades, in the stomach, or in the chest; shortness of breath, hoarseness or inability to properly speak; difficulty swallowing or eating food; pain in the jaw or upper neck (for thoracic aneurysms); and a tender or pulsating mass in the stomach that can be externally felt (for an abdominal aneurysm).
Aortic aneurysms develop due to weakness in the wall of the aorta, which is a condition that may be present at birth or develop as the result of a related condition or injury. The true cause of an aortic aneurysm is very difficult for doctors to discern, and in most cases neither the doctor or the patient will ever know.
Atherosclerosis, also known as hardening of the arteries, weakens artery walls and is a major cause of aneurysms as well as heart attacks and strokes. In this condition, a fatty plaque-like substance - cholesterol - adheres to the walls of the aorta, later calcifying and weakening the artery's thick walls.
Other potential causes of aortic aneurysms include high blood pressure, which puts increased pressure on the walls of the aorta over time, and diabetes, which damages blood vessels and leaves them vulnerable to a number of serious conditions. Many conditions present at birth, including Marfan syndrome, can cause congenital abnormalities which trigger degenerative damage to the walls of the aorta, particularly the medial layer of the blood vessel wall. Blunt force injuries to the chest or abdomen can cause abdominal or thoracic aortic aneurysms by weakening the walls of the artery themselves.
Diagnosis & Tests
Because most aortic aneurysms display no physical symptoms, many are detected when patients are undergoing unrelated tests for other conditions or diseases. The symptoms for aortic aneurysms are extremely general, but because a ruptured or exploded aneurysm is a life-threatening occurrence, most doctors screen for aneurysms soon after patients complain of symptoms.
There are several tests that doctors employ to locate aneurysms. Magnetic resonance imaging (MRI) tests and computed tomography (CT) scans are two of the most commonly administered methods, but many medical professionals also use ultrasound exams to get a view inside of the patient's body and locate the aneurysm.
Doctors who use the angiography method employ a dye test that examines the aorta and is able to locate strange bulges or abnormalities in the artery's walls. This test is the easiest way to tell if an aneurysm is fusiform, meaning that it is uniform in shape and runs along an extended piece of the aorta, or saccular, meaning that it is lopsided and only occurs on one side of the aorta where a wall has been weakened. The doctor may also perform an EKG exam early in the process to rule out the possibility of a serious heart condition or heart attack.
Treatment & Therapy
Aneurysms that are small and pose no immediate threat are monitored by a physician during follow-up visits to the doctor; if the aneurysm grows to a certain size, usually about 5.5 centimeters, then action must be taken to remove it surgically. Surgical approaches differ greatly and are catered to the individual patient, but most surgeries involve removing the weakened part of the blood vessel and grafting on an artificial replacement to the aorta's wall.
Depending on the location of the surgery, other replacements may be needed: for example, if the surgery occurs close to the aortic valve, most surgeons will recommend replacing that valve. The surgical procedures are complicated and usually require either open-chest or abdominal surgery. In many cases, medication will also be given to lower blood pressure. Among these, beta blockers reduce the stress on the aortic wall and allow the body to attempt to heal itself without surgical interference.
Prevention & Prophylaxis
A low-fat diet, low-cholesterol diet, regular exercise and avoidance of cigarettes will aid people at risk of developing aortic aneurysms. People with atherosclerosis or congenital heart defects should receive regular medical check-ups from their physicians.