Aortic Aneurysms
An aortic aneurysm is a bulging or ballooning in the wall of the aorta. It is caused when a portion or all layers of the aortic wall weakens. The cause of aortic aneurysms is probably related to multiple risk factors, which are commonly found in patients with thoracic and abdominal aneurysms. The risk factors identified are smoking, high blood pressure, atherosclerosis, and genetic connective disorders (i.e. Marfan’s Syndrome, and Ehlers-Danlos syndrome). Thoracic aortic aneurysms are more likely to occur in men than in women and in patients with chronic obstructive pulmonary disease (COPD). Degenerative aortic aneurysms are the most common type of aneurysms, which are found in the aging population. The aortic wall undergoes changes that involve reduction in the structural framework and strength of the aorta. As the diameter of the aorta increases and the wall thickness decreases, the aortic wall stress increases resulting in a higher probability of rupture or dissection.
The most common anatomical location for an aortic aneurysm is in the abdomen and secondly in the descending thoracic aorta. Oftentimes, thoracic aortic aneurysms are found incidentally, however some patients may present with non-specific pain or other symptoms related to compression of other organs as a result of the expanding aneurysm. A common scenario which thoracic aortic aneurysms are discovered is on a plain chest x-ray or chest CT scan performed for another diagnosis.
Surveillance Program
If the likelihood of an aneurysm rupturing is low it should then be carefully watched and measures taken to reduce the rate at which it enlarges. For the past fifteen years, we have maintained a program of careful follow-up of patients with small aneurysms. The patient receives a computerized tomography scan (CT scan) every six or 12 months that provides detailed measurements of all areas of the aorta including diameters and volume. Rapid changes in the size of an aneurysm or gradual enlargement to a dangerous size are promptly detected, and elective surgery recommended. In those patients whose aneurysms do not require operation, control of factors that influence the rate at which an aneurysm enlarges can postpone the need for surgery. Medical therapy includes careful control of high blood pressure, cessation of cigarette smoking, and participation in a program of moderate aerobic exercise.