Aneurysm Screening and Surgery
Abdominal Aortic Aneurysm
What is an abdominal aortic aneurysm (AAA)?
The aorta is the largest artery in your body, and it carries oxygen-rich blood pumped out of, or away from, your heart. Your aorta runs through your chest, where it is called the thoracic aorta. When it reaches your abdomen, it is called the abdominal aorta. The abdominal aorta supplies blood to the lower part of the body. In the abdomen, just below the navel, the aorta splits into two branches, called the iliac arteries, which carry blood into each leg.
When a weak area of the abdominal aorta expands or bulges, it is called an abdominal aortic aneurysm (AAA). The pressure from blood flowing through your abdominal aorta can cause a weakened part of the aorta to bulge, much like a balloon. A normal aorta is about 1 inch (or about 2 centimeters) in diameter. However, an AAA can stretch the aorta beyond its safety margin as it expands. Aneurysms are a health risk because they can burst or rupture. A ruptured aneurysm can cause severe internal bleeding, which can lead to shock or even death.
Less commonly, AAA can cause another serious health problem called embolization. Clots or debris can form inside the aneurysm and travel to blood vessels leading to other organs in your body. If one of these blood vessels becomes blocked, it can cause severe pain or even more serious problems, such as limb loss.
Each year, physicians diagnose approximately 200,000 people in the United States with AAA. Of those 200,000, nearly 15,000 may have AAA threatening enough to cause death from its rupture if not treated.
Fortunately, especially when diagnosed early before it causes symptoms, an AAA can be treated, or even cured, with highly effective and safe treatments.
What are the symptoms?
Although you may initially not feel any symptoms with AAA, if you develop symptoms, you may experience one or more of the following:
- A pulsing feeling in your abdomen, similar to a heartbeat
- Severe, sudden pain in your abdomen or lower back. If this is the case, your aneurysm may be about to burst
- On rare occasions, your feet may develop pain, discoloration, or sores on the toes or feet because of material shed from the aneurysm
If your aneurysm bursts, you may suddenly feel intense weakness, dizziness, or pain, and you may eventually lose consciousness. This is a life-threatening situation and you should seek medical attention immediately.
What causes an abdominal aortic aneurysm?
Physicians and researchers are not quite sure what actually causes an AAA to form in some people. The leading thought is that the aneurysm may be caused by inflammation in the aorta, which may cause its wall to weaken or break down. Some researchers believe that this inflammation can be associated with atherosclerosis (also called hardening of the arteries) or risk factors that contribute to atherosclerosis, such as high blood pressure (hypertension) and smoking. In atherosclerosis, fatty deposits, called plaque, build up in an artery. Over time, this buildup causes the artery to narrow, stiffen and possibly weaken. Besides atherosclerosis, other factors that can increase your risk of AAA include:
- Being a man older than 60 years
- Having an immediate relative, such as a mother or brother, who has had AAA
- Having high blood pressure
Your risk of developing AAA increases as you age. AAA is more common in men than in women.
What tests will I need?
Abdominal aortic aneurysms that are not causing symptoms are most often found when a physician is performing an imaging test, such as an ultrasound or CT scan, for another condition. Sometimes your physician may feel a large pulsing mass in your abdomen on a routine physical examination. If your physician suspects that you may have AAA, he or she may recommend one of the following tests to confirm the suspicion:
- Abdominal ultrasound
- Computed tomography (CT) scan
- Magnetic resonance imaging (MRI)
How is an abdominal aortic aneurysm treated?
If your AAA is small, your physician may recommend “watchful waiting,” which means that you will be monitored every 6-12 months for signs of changes in the aneurysm size. Your physician may schedule you for regular CT scans or ultrasounds to watch the aneurysm. This method is usually used for aneurysms that are smaller than about 2 inches (roughly 5.0 to 5.5 centimeters) in diameter. If you also have high blood pressure, your physician may prescribe blood pressure medication to lower the pressure on the weakened area of the aneurysm. If you smoke, you should obtain help to stop smoking. An aneurysm will not “go away” by itself. It is extremely important to continue to follow up with your physician as directed because the aneurysm may enlarge to a dangerous size over time. It could eventually burst if this is not detected and treated.
Open Surgical aneurysm repair
A vascular surgeon may recommend that you have a surgical procedure called open aneurysm repair if your aneurysm is causing symptoms, is larger than about 2 inches (roughly 5.0 to 5.5 centimeters), or is enlarging under observation. During an open aneurysm repair, also known as surgical aneurysm repair, your surgeon makes an incision in your abdomen and replaces the weakened part of your aorta with a tube-like replacement called an aortic graft. This graft is made of a strong, durable, man-made plastic material, such as Dacron®, in the size and shape of the healthy aorta. The strong tube takes the place of the weakened section in your aorta and allows your blood to pass easily through it. Following the surgery, you may stay in the hospital for 4 to 7 days. Depending upon your circumstances, you may also require 6 weeks to 3 months for a complete recovery. More than 90 percent of open aneurysm repairs are successful in the long term.
Endovascular stent graft
Instead of open aneurysm repair, your vascular surgeon may consider a newer procedure called an endovascular stent graft. Endovascular means that the treatment is performed inside your artery using long, thin tubes called catheters that are threaded through your blood vessels. This procedure is less invasive, meaning that your surgeon will usually need to make only small incisions in your groin area through which to thread the catheters. During the procedure, your surgeon will use live X-ray pictures viewed on a video screen to guide a fabric and metal tube, called an endovascular stent graft (or endograft), to the site of the aneurysm. Like the graft in open surgery, the endovascular stent graft also strengthens the aorta. Your recovery time for endovascular stent grafting is usually shorter than for open surgery, and your hospital stay may be reduced to 2 to 3 days. However, this procedure requires more frequent follow-up visits with imaging procedures, usually CT scans, after endograft placement to be sure the graft continues to function properly. Also, the endograft is more likely to require periodic maintenance procedures than the open procedure. In addition, your aneurysm may not have the shape that is suitable for this procedure, since not all patients are candidates for endovascular repair because of the extent of the aneurysm, its relationship to the renal (kidney) arteries, or other issues. While the endovascular stent graft may be a good option for some patients who have suitable aneurysms and who have medical conditions increasing their risk, in some other cases, open aneurysm repair may still be the best way to cure AAA. Your vascular surgeon will help you decide what is the best method of treatment for your particular situation.
Thoracic Aortic Aneurysm
What is a thoracic aortic aneurysm?
The aorta is the largest artery in your body, and it carries blood away from your heart to all the parts of your body. The part of your aorta that runs through your chest is called the thoracic aorta and, when your aorta reaches your abdomen, it is called the abdominal aorta. When a weak area of your thoracic aorta expands or bulges, it is called a thoracic aortic aneurysm (TAA). Approximately 25 percent of aortic aneurysms occur in the chest, and the rest involve the abdominal aorta.
Thoracic aortic aneurysms are serious health risks because they can burst or rupture. A ruptured aneurysm can cause severe internal bleeding, which can rapidly lead to shock or death.
Thoracic aneurysms affect approximately 15,000 people in the United States each year. Some patients may have more than one TAA or may also have an aneurysm in the abdominal aorta. Only about 20 to 30 percent of patients who get to the hospital with a ruptured TAA survive. For this reason, it is crucial to treat large aneurysms early, in order to prevent their rupture.
What are the symptoms?
You may not feel any symptoms with TAA. Very few patients with TAA notice symptoms.
If you do have symptoms, they will depend on where your aneurysm is located and how large it is. Possible symptoms include:
- Pain in the jaw, neck, and upper back
- Chest or back pain
- Coughing, hoarseness, or difficulty breathing
If your aneurysm is large and in the section of the aorta closest to the heart, it may affect your heart valves and lead to a condition called congestive heart failure.
It is critical to notify your physician immediately if you experience any symptoms of TAA. If left untreated, these conditions may lead to a fatal rupture or organ damage. This is a life-threatening situation and you should seek medical attention immediately.
What causes a thoracic aortic aneurysm?
It is not known why aortic aneurysms occur, but researchers understand some of the factors that contribute to their development. There certainly is a genetic component to many aneurysms that develop, and family members of people with aneurysms are at higher risk of developing one. While we do not know what triggers aneurysm development in most cases, the ultimate outcome is the destruction of the aortic wall, which weakens the wall, and then ballooning out of the aneurysm. Factors that may increase your risk for aneurysm formation include:
- High blood pressure
- Having a family history of aneurysms
In addition, aortic aneurysms may also develop due to aortic dissection, which is typically associated with high blood pressure. An aortic dissection occurs when blood flow forces the layers of the wall of your aorta apart, which weakens your aorta. The separation can extend from your thoracic aorta through your entire aorta and block arteries to your legs, arms, kidneys, brain, spinal cord, and other areas. Another problem associated with aortic dissection is that over time, the pressure of blood flow can cause the weakened area of your aorta to bulge like a balloon. Much like an over-inflated balloon, an aneurysm can stretch the aorta beyond its safety margin.
Symptoms of an aortic dissection include chest and/or back pain. It can often mimic the symptoms of a heart attack. If you experience chest or back pain, you should notify your physician immediately.
Certain other diseases can weaken the layers of the aortic wall, increasing the risk of aneurysms. These diseases include:
- Marfan’s syndrome, a connective tissue disorder
Rarely, trauma, such as a fall or rapid deceleration in a motor vehicle accident, may cause TAA.
Your risk of developing TAA increases as you age. TAA is more common in men than in women. The larger your TAA, or the faster it grows, the more likely it is to rupture. The chance of rupture increases when your aneurysm is larger than about twice the normal diameter.
What tests will I need?
Your physician will order one or more of the following tests to diagnose TAA:
- Chest x-ray
- Echocardiography (an ultrasound of the heart)
- Magnetic resonance imaging (MRI)
- Computed tomography (CT) scan
How is a thoracic aortic aneurysm treated?
If your TAA is small and not causing symptoms, your physician may recommend “watchful waiting,” which means that you will be monitored every 6 months for signs of changes in your aneurysm. Your physician may schedule you for CT or MRI scans every 6 months to watch the aneurysm. CT scans take X-ray pictures of slices of your body. This test can help your physician monitor the size and shape of your aneurysm. This method is usually used for aneurysms that are smaller than about 2 inches across. If you also have high blood pressure, your physician may prescribe blood pressure medication to lower your overall blood pressure and the pressure on the weakened area of the aneurysm.
However, if your TAA is large or causing symptoms, you need active and prompt treatment to prevent rupture. Your vascular surgeon may recommend actively treating your aneurysm if it is large, grows quickly, or you have certain other types of disease. For example, if you have Marfan’s syndrome, you may require active treatment sooner than patients who have small TAAs but do not have Marfan’s syndrome. The active treatments for TAA are open surgical aneurysm repair and endovascular stent-graft repair.
Open Surgical Repair
During open aneurysm repair, your surgeon makes an incision in your chest and replaces the weakened portion of your aorta with a fabric tube, called a graft. The graft is stronger than the weakened aorta and allows blood to pass through it without causing a bulge. Many patients who have a TAA also have heart disease or involvement of the aorta adjacent to the heart. For extensive or complex thoracic aneurysms, sometimes heart surgery is required at the same time as open aneurysm repair depending upon the particular situation.
Following the surgery, you may stay in the hospital for 7 to 10 days. If your aneurysm is extensive or complex, or if you have other conditions such as heart, lung or kidney disease, you may require 2 to 3 months for a complete recovery.
Endovascular Stent Graft Repair
Instead of open aneurysm repair, if your aneurysm location and shape are suitable, your vascular surgeon may consider a promising, newer procedure called an endovascular stent graft. Endovascular means that the treatment is performed inside your body using long, thin tubes called catheters. The catheters are inserted in small incisions in your groin, and sometimes your arms, and are guided through your blood vessels. During the procedure, your surgeon will use live X-ray pictures viewed on a video screen to guide a stent graft to the site of your aneurysm. Like the graft used in open surgery, this stent graft allows blood to flow through your aorta without putting pressure on the damaged wall of your aneurysm. This keeps your aneurysm from rupturing. Over time, your aneurysm usually will shrink. Endovascular stent-graft repair requires a shorter recovery time than open aneurysm repair, and your hospital stay is reduced to 2 of 3 days. However, this treatment may not be applicable to all TAAs, since your aneurysm must have a suitable shape to allow the stent graft to be used effectively. With the endovascular stent-graft repair, it is particularly important that long-term follow-up with periodic scans of the aortic repair be done to be sure that the stent-graft is functioning properly. Sometimes further procedures are required to maintain the stent graft if leaks develop or if it moves out of position. Experts are still studying the long-term results of endovascular stent-graft repair.
Your vascular surgeon will advise you regarding the best option for your particular situation.
What are peripheral aneurysms?
When a weak area of a blood vessel expands or bulges significantly, physicians call it an aneurysm. Most aneurysms occur in the aorta, your body’s largest artery. The aorta carries blood away from your heart to the rest of your body. The part of your aorta located in your chest is called the thoracic aorta, and when your aorta reaches your abdomen, it is called the abdominal aorta.
Peripheral aneurysms affect the arteries other than the aorta. Most peripheral aneurysms occur in the popliteal artery, which runs down the back of your lower thigh and knee. Less commonly, peripheral aneurysms also develop in the femoral artery in your groin, the carotid artery in your neck, or sometimes the arteries in your arms. A special type of peripheral aneurysm that forms in the arteries feeding the kidneys or the bowel is called a visceral aneurysm.
If you have a peripheral aneurysm in one leg, you are more likely to have an aneurysm in the other leg. You also have a greater chance of having an aortic aneurysm.
Aortic aneurysms can cause serious complications because they can burst or rupture. Peripheral aneurysms do not rupture as often as aortic aneurysms, although they can do so. However, peripheral aneurysms more commonly can form clots that may block blood flow to your limbs or brain. Peripheral aneurysms, especially if they are large, can also compress a nearby nerve or vein and cause pain, numbness, or swelling.
What are the symptoms?
You may not feel symptoms with a peripheral aneurysm, especially if it is small. Two out of 3 patients with a peripheral aneurysm may not notice any symptoms.
If you do have symptoms, the warning signs will depend on the location and size of your aneurysm. Possible symptoms include:
- A pulsating lump that you can feel
- Leg or arm pain or cramping with exercise, called claudication
- Leg or arm pain with rest
- Painful sores or ulcerations involving the toes or fingers
- Radiating pain or numbness in your leg or arm, which is caused by nerve compression
- Gangrene, or tissue death, which results from a severe blockage in your limb and usually requires some form of amputation
If the carotid artery is involved, the symptoms can include transient ischemic attacks (TIA) or stroke. These are described in the sections on carotid or cerebrovascular disease. If the bowel arteries are involved, the symptoms can be similar to those for mesenteric ischemia and are described in the section on mesenteric ischemia.
What causes peripheral aneurysms?
Peripheral aneurysms may be caused by infection or injury in unusual circumstances, but the actual cause of most peripheral aneurysms is not known with certainty. Researchers believe that atherosclerosis, also called “hardening of the arteries,” is associated with many peripheral aneurysms. Your arteries are normally smooth and unobstructed on the inside but, as you age, they can become blocked through atherosclerosis. In atherosclerosis, a sticky substance called plaque builds up in the walls of your arteries. Over time, your arteries narrow, stiffen and possibly weaken. Factors that increase your risk for atherosclerosis include:
- High blood pressure
- High cholesterol
- Having a family history of heart or vascular disease
Your risk of developing peripheral aneurysms also increases as you age. People are usually in their 60s and 70s when they are found to have peripheral aneurysms.
What tests will I need?
First your physician will usually ask questions about your general health, medical history, and symptoms. In addition, your physician conducts a physical examination. Together these events are known as patient history and exam. As part of your history and exam, your physician may check for an aneurysm in your groin or thigh.
If your physician suspects you have a peripheral aneurysm, he or she may order an ultrasound or other imaging test, such as a computed tomography (CT) or magnetic resonance imaging (MRI) scan to confirm it. Angiography, which is more invasive, may be required in some circumstances to plan surgery or deliver medications if this is required.
It is known that many patients who have a peripheral aneurysm also have heart disease. Before performing surgery to treat your peripheral aneurysm, your physician may order tests to check on your heart, such as an electrocardiogram (ECG) or stress test.
How are peripheral aneurysms treated?
Your treatment will depend on the location of your aneurysm, the size of your aneurysm, your symptoms, and whether or not the aneurysm is completely blocked by clots at the time of its discovery. For example, if you have a popliteal aneurysm that is blocked and yet you are having no symptoms, you may not need surgery. In that situation, for example, your physician may recommend that you:
- Control your risk factors for atherosclerosis
- Walk regularly to keep blood flowing in your leg arteries
- Do not cross your legs or squat
- Practice foot care by cleansing your feet regularly and watching out for sores that don’t heal (a sign of poor circulation)
Although a popliteal aneurysm that is not blocked may rarely burst, more often it can suddenly become blocked without warning and obstruct the flow of blood to the lower leg. It can also be a source for clots or other debris to break off from inside the aneurysm and travel down the leg arteries to lodge and obstruct blood flow into the foot. Each of these developments can lead to pain and ulceration and, potentially, to amputation of the limb. As a result, if you have a popliteal or femoral aneurysm that is still open, you will need repair of the aneurysm. This is usually done with open surgery but endovascular treatment may be an option in some circumstances. Arm or carotid aneurysms have similar behavior but the symptoms they cause will involve the hand, with pain or ulcer formation, or the brain, with stroke or transient neurological symptoms, respectively.
Vascular surgeons usually treat peripheral aneurysms with a surgical bypass or replacement. During this operation, your vascular surgeon constructs a new pathway for blood to flow by using a graft. A bypass graft may be made from a portion of one of your veins or sometimes a man-made tube, formed from plastic or other materials, that your surgeon connects above and below the aneurysm to allow blood to pass around it. If you need bypass surgery, you will receive regional or general anesthesia. Following the surgery, depending upon the location of your aneurysm, you may need to stay in the hospital for 2 to 7 days.
In some circumstances, if a peripheral aneurysm is blocked by a clot, medications known as thrombolytic agents may be used to dissolve the clots in preparation for bypass surgery. This procedure is sometimes done at the time of angiography if needed.
The use of endovascular therapy, such as stent grafts, for the treatment of peripheral aneurysms is still in the investigational stages. Nevertheless, endovascular therapy may have a role in the treatment of some patients with peripheral aneurysms, especially if the risk for surgical repair is felt to be too high and the aneurysm has a favorable location and shape for an endovascular graft.
Very rarely, some patients with popliteal or femoral aneurysms may initially have a limb that is beyond saving because of extensive gangrene or infection or they may be too sick to undergo bypass surgery. In these cases, the vascular surgeon may need to perform an amputation as a last resort.