An aneurysm can occur in many parts of the artery, the organ that is responsible for the flow of oxygen-rich blood from the heart to the other parts of the body. An aortic aneurysm happens when a section of the aorta, the body’s main artery, expands, or balloons. As an aneurysm continues to enlarge, the walls of the aorta stretch making them much thinner. Untreated, aneurysms may rupture, causing potentially fatal bleeding. Aneurysms occurring within the chest, or thorax region of the body, are called thoracic aortic aneurysms (TAA). Other names are descending aortic aneurysm, thoracic aortic dissection or thoracic aneurysm.
Causes and Symptoms of Thoracic Aortic Aneurysm
The most common cause of TAA is hardening of the arteries, or atherosclerosis. Other causes include aging, inflammation of the aorta, injury from falls or other trauma and certain genetic conditions, such as Marfan syndrome in which an enlarged aorta is found. Syphilis is another risk factor. In addition, family medical history accounts for about 20% of cases, according to the Society for Vascular Surgery (SVS). Adding to all of these risk factors are smoking and high blood pressure (hypertension).
It is possible that no symptoms will occur until the aorta begins to expand or to “leak” blood onto other tissues. When symptoms do arise, they can include hoarseness, pain or swelling in the back, chest pain, rapid heart rate or the feeling of impending doom. Nausea, clammy skin or problems swallowing may also signal TAA, as can vomiting and high-pitched breathing (wheezing).
Several methods can be used to diagnose TAA. Computed tomography (CT) scans, magnetic resonance imaging (MRI), and chest X-rays are among them. A cardiologist may also use an echocardiogram or transesophageal echocardiogram to confirm the diagnosis.
Several Treatment Options Exist
If an aneurysm is discovered early, is still small (less than 5.5 centimeters), and no symptoms have occurred, surgery may not yet be necessary. The vascular surgeon will closely monitor the aneurysm growth every six to twelve months with CT scans. Additionally, it is important to quit smoking and to control risk factors, such as high blood pressure or high cholesterol, with medication.
An aneurysm that has reached 5.5-6 centimeters presents a much higher risk of rupture and surgery is recommended. With the traditional open repair of TAA, an incision is made into the chest or just under the breastbone to visualize the area of the aneurysm. The aneurysm is opened and a cylinder-like tube called a graft is placed within the aorta to repair it. Ultimately, the weakened area of the artery is relined with a sleeve of material to strengthen it and prevent rupture of the aneurysm. At times, there is also involvement of the aorta adjacent to the heart. If this is the case, sometimes heart surgery may be required at the same time. Hospital stay with this procedure is about 7-10 days, with full recovery depending on other conditions present.
Endovascular stent grafting is a less invasive option. Intervention through the bilateral groin region allows for deployment of stent grafts with minimal recovery time. This repair may only be used if the location and shape of the aneurysm is suitable to allow for correct deployment of the graft. This repair involves a small incision in the groin. Under guidance of an x-ray, a small catheter is placed through the groin incision and used to pass a graft up into the aneurysm. This graft is placed so that the ends fit neatly into the non-diseased portion of the artery at the opposite ends of the aneurysm. This is relining the weakened area of the aorta with a strong sleeve of material, thus preventing rupture of the aneurysm.
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