Statistics in the United States show that about 15,000 people are affected by thoracic aortic aneurysms each year and that this condition is the 13th leading cause of death in that country. Fifty percent of patients who experience a rupture of a thoracic aortic aneurysm die before reaching the hospital. Furthermore, a surgical repair of a ruptured thoracic aneurysm carries a 25-50 percent mortality. If complications, such as kidney failure, occur after surgery, the prognosis (outlook) is particularly poor.
Thoracic aortic aneurysms are not commonly known to Filipinos, who are more familiar with cerebral aneurysms that rupture and cause brain hemorrhage. The type of aneurysm that the First Gentleman Mike Arroyo had, on the other hand, involves the aorta, the great artery that carries blood from the heart to the rest of the body ( refer to Figure 1 below). The aorta bulges at the site of the aneurysm like a weak spot on an old worn tire. Rupture of the aneurysm is the most dreaded catastrophic complication, producing profuse bleeding that leads to shock. Death may rapidly follow.
Here are the most frequently asked questions about this condition:
What are the causes of thoracic aortic aneurysms?
The main cause of aortic aneurysms is arteriosclerosis (hardening of the arteries). At least 80 percent of aortic aneurysms are arteriosclerotic. The arteriosclerosis can weaken the aortic wall and the pressure of the blood being pumped through the aorta causes expansion at the site of weakness.
What are the symptoms of a thoracic aortic aneurysm?
Thoracic aortic aneurysm may be asymptomatic (without symptoms) or symptomatic (with symptoms). Symptoms may be related to the location, size, and growth rate of the aneurysm. Those of an aortic arch aneurysm may include, but are not limited to, the following:
• Wheezing, coughing, or shortness of breath as a result of pressure on the trachea (windpipe)
• Coughing up blood (hemoptysis)
• Hoarseness as a result of pressure on the vocal cords
• Difficulty swallowing (dysphagia) due to pressure on the esophagus
• Pain in the chest and/or back
Most thoracic aneurysms, however, are asymptomatic and typically detected only when imaging studies (chest x-rays, CT scans, MRI, etc.) are being obtained for unrelated reasons. However, a rupture of these aneurysms produces dramatic symptoms. A ripping sensation within the chest, accompanied by severe pain in the back between the shoulder blades, is the most typical complaint. Dizziness, difficulty walking and speaking can all accompany this acute event.
What are the causes and symptoms of aortic dissection? How is it diagnosed?
The cause of aortic aneurysm is still under investigation. However, there are several risk factors associated with aortic dissection, such as:
• Hypertension (high blood pressure)
• Connective tissue disorders
• Cystic medical disease (a degenerative disease of the aortic wall)
• Aortitis (inflammation of the aorta)
• Atherosclerosis
• Bicuspid aortic valve
• Trauma
• Coarctation of the aorta (narrowing of the aorta)
• Hypervolemia (excess fluid or volume of the circulation)
• Polycystic kidney disease
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.
The diagnostic procedures for the diagnosis of an aortic dissection include the following:
• Computed tomography scan (also called CT or CAT scan) ( refer to Figure 2, left), and
• Transesophageal echocardiogram (TEE), a diagnostic procedure that uses echocardiography to assess the heart’s function and structures
Dissecting aneurysm occurs when a tear begins within the wall of the aorta, causing the three layers to separate, similar to what happens to plywood that is left out in the weather ( refer to Figure 3, left, on Page D-2). The dissection (separation of the layers) causes the wall of the aorta to weaken, and the aorta enlarges. Although dissections are uncommon, they are the most common of the acute aortic syndromes. They are lethal if not treated.
How is thoracic aortic aneurysm treated with surgery?
The current standard surgical treatment of a thoracic aortic aneurysm is the open-chest approach. The main purpose of open chest surgery to treat a thoracic aneurysm is to replace the weakened portion of the aorta with a fabric tube, called a graft (refer to Figure 4, right). However, the threatened rupture of aortic aneurysms, such as in a dissection, represents a life-threatening emergency which is typically treated with emergency surgery. Replacing a thoracic aneurysm is surgically complicated and requires an experienced thoracic surgical team. The surgery involves removing the aneurismal portion of the aorta and replacing it with an artificial Dacron tube. Newer surgical procedures include minimally invasive surgical techniques in which, instead of dividing the breastbone, only the upper part of the sternum is divided. This allows for less blood loss and quicker recovery. Another new, promising procedure utilized in some thoracic and thoracoabdominal aneurysms uses an endovascular stent or endoprosthesis device. Endovascular means that the surgery is performed inside your body using thin, long tubes called catheters. By entering through small incisions in the groin, the catheters guide a stent graft through the blood vessels to the site of the aneurysm. This creates a new pathway for blood flow, taking the pressure off the aneurysm.
What are the risks of thoracic aortic aneurysm surgery?
The risks involved in repairing a thoracic aneurysm surgery depend on the extent of the repair required, the length of surgery, and the patient’s overall general health. Complications after thoracic aneurysm surgery may include:
• Heart attack
• Irregular heartbeats
• Bleeding
• Stroke
• Paralysis due to injury of the spinal cord
• Graft infection
• Kidney damage
How long will it take to recover from thoracic aortic aneurysm surgery?
The length of hospital stay following thoracic aneurysm surgery depends on the patient’s condition and the operation performed. Most people need at least four to six weeks to recover from thoracic aneurysm surgery. If the aneurysm is extensive, involves intervention to repair other complications of if the patient has other conditions such as heart, lung, or kidney disease, recovery may take two to three months. They may need a program of medical rehabilitation to prevent complications and facilitate functional improvements.
What should patients do after they have recovered?
After the surgical repair of the aneurysm, it is recommended that the patient adopts a heart-healthy lifestyle similar to those of other heart surgery patients. These include:
• Losing weight if overweight or obese
• Quitting cigarette smoking
• Lowering high blood cholesterol
• Controlling blood sugar if diabetic
• Maintaining blood pressure to normal levels
• Controlling dietary fat intake
• Taking medications to control such factors as hyperlipidemia (elevated levels of fats in the blood) and/or high blood pressure.