Abdominal Aortic Aneurysm: Q & A
A Q&A with Dr. Frank Pomposelli, Chief, Division of Vascular Surgery at The CardioVascular Institute at Beth Israel Deaconess Medical Center
What is an abdominal aortic aneurysm (AAA)?
The aorta is the largest artery in your body, and it carries blood 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 your internal organs and the lower part of the body. In the lower abdomen, the aorta splits into two branches (the iliac arteries) that carry blood into each leg.
When a weak area of the abdominal aorta expands or bulges, it is called an abdominal aortic aneurysm. 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 to many times this size. As the aorta enlarges and the wall gets progressively thinner and tauter, it can potentially rupture, a devastating complication that is often fatal.
What causes AAA?
The cause of AAA is unknown and has been the subject of intense research over many years. The leading theory is that aneurysms may be caused by degradation of elastin, a component of the wall of the aorta that gives it both its strength and elasticity. Some researchers believe that aneurysms are a variant of atherosclerosis (also called hardening of the arteries). In atherosclerosis, fatty deposits, called plaque, build up in an artery. Over time, this buildup can block the flow of blood through the artery and cause the wall to stiffen. How atherosclerosis may cause aneurysms is not entirely clear, however many patients with AAA also have evidence of atherosclerosis and both problems share the many of the same risk factors including:
What are the symptoms of AAA?
Aneurysms develop slowly over many years and usually cause no symptoms. Rupture is commonly the first symptom of AAA and usually occurs without warning. Occasionally patients will experience some pain prior to rupture usually in the abdomen, flank area or back. The symptoms of rupture include:
Aortic rupture is a true emergency and requires immediate treatment. If you have any of the above symptoms you should call your physician or seek evaluation in the emergency room. It is important to remember that AAA is rare in someone under the age of 60 and that the vast majority of patients with abdominal pain will have some other problem. If you are known to have an AAA and you experience unusual abdominal or back pains or the other symptoms associated with rupture you should call 9-1-1 immediately.
How is AAA treated?
If the aneurysm is small and there are no symptoms (for example, if it was discovered during a routine physical), your doctor may recommend periodic evaluation. In general, this is simply done with a painless abdominal ultrasound on an annual or semiannual basis. Once the AAA has reached a size where treatment is being considered a CT scan or MRI may be ordered.
The risk of rupture of AAA is directly related to the size of the aneurysm. Ultrasound examination is very effective at both determining the presence and size of AAA in most people. Surgery is recommended for patients with aneurysms bigger than 5.5 cm in diameter and aneurysms that rapidly increase in size. The goal is to perform surgery before rupture occurs.
There are two approaches to surgery. In a traditional (open) repair, a large incision is made in your abdomen and the abnormal section of the aorta is replaced with a graft made of synthetic material, such as Dacron or Teflon. Although safe and remarkably effective, open AAA surgery is a lengthy operation with a long recovery period and may not be feasible in some patients due to associated health problems or advanced age.
The other approach is called endovascular stent grafting. An endovascular stent graft is a tube composed of fabric supported by a metal mesh called a stent. Using a combination of minor surgery and x-ray imaging called angiography, the stent graft is introduced into the inside of the aorta from a small incision in the femoral artery in the groin through the iliac arteries. When deployed, it seals tightly with the normal aorta above and the iliac arteries below the aneurysm. The stent graft excludes the aneurysm from circulating blood by allowing blood flow to pass through it. This prevents the aneurysm from bursting.
Stent grafting has the advantage of being less invasive than open surgery, has shorter convalescence and can be safely done in patients thought to be too sick or old for conventional surgery. The shape and extent of some aneurysms make them unsuitable for this approach.
How do I prevent AAA?
There is no known way to prevent AAA, however treatment before rupture occurs is the best way to prevent death or serious complications. Understanding the risk factors for AAA and regular follow-up with your physician or vascular surgeon to monitor for enlargement and appropriate treatment when indicated is the best way to prevent rupture. In addition, proper treatment of hypertension and stopping smoking may slow the rate of enlargement of AAA. In the future there may be medications available that will be used to slow or retard the enlargement of AAA, however no such medication is currently available. It is known that AAA can occur in families in 10 to 20 percent of cases presumably as an inherited trait, although how this is passed from generation to generation is unknown. As a general rule, if your father, mother, sibling or grandparent has had an AAA, an abdominal ultrasound should be performed periodically once you reach the age of 50 or 55.
Above content provided by Beth Israel Deaconess Medical Center.
For advice about your medical care, consult your doctor.
Posted January 2009
What is an abdominal aortic aneurysm (AAA)?
The aorta is the largest artery in your body, and it carries blood 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 your internal organs and the lower part of the body. In the lower abdomen, the aorta splits into two branches (the iliac arteries) that carry blood into each leg.
When a weak area of the abdominal aorta expands or bulges, it is called an abdominal aortic aneurysm. 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 to many times this size. As the aorta enlarges and the wall gets progressively thinner and tauter, it can potentially rupture, a devastating complication that is often fatal.
What causes AAA?
The cause of AAA is unknown and has been the subject of intense research over many years. The leading theory is that aneurysms may be caused by degradation of elastin, a component of the wall of the aorta that gives it both its strength and elasticity. Some researchers believe that aneurysms are a variant of atherosclerosis (also called hardening of the arteries). In atherosclerosis, fatty deposits, called plaque, build up in an artery. Over time, this buildup can block the flow of blood through the artery and cause the wall to stiffen. How atherosclerosis may cause aneurysms is not entirely clear, however many patients with AAA also have evidence of atherosclerosis and both problems share the many of the same risk factors including:
- being a man older than 60 years old
- high blood pressure
- smoking
What are the symptoms of AAA?
Aneurysms develop slowly over many years and usually cause no symptoms. Rupture is commonly the first symptom of AAA and usually occurs without warning. Occasionally patients will experience some pain prior to rupture usually in the abdomen, flank area or back. The symptoms of rupture include:
- a painful pulsating sensation in the abdomen
- pain in the abdomen or back, which may radiate to the groin, buttocks or legs
- muscle stiffness in the abdomen
- anxiety
- nausea and vomiting
- clammy skin
- rapid heart rate
- shock
Aortic rupture is a true emergency and requires immediate treatment. If you have any of the above symptoms you should call your physician or seek evaluation in the emergency room. It is important to remember that AAA is rare in someone under the age of 60 and that the vast majority of patients with abdominal pain will have some other problem. If you are known to have an AAA and you experience unusual abdominal or back pains or the other symptoms associated with rupture you should call 9-1-1 immediately.
How is AAA treated?
If the aneurysm is small and there are no symptoms (for example, if it was discovered during a routine physical), your doctor may recommend periodic evaluation. In general, this is simply done with a painless abdominal ultrasound on an annual or semiannual basis. Once the AAA has reached a size where treatment is being considered a CT scan or MRI may be ordered.
The risk of rupture of AAA is directly related to the size of the aneurysm. Ultrasound examination is very effective at both determining the presence and size of AAA in most people. Surgery is recommended for patients with aneurysms bigger than 5.5 cm in diameter and aneurysms that rapidly increase in size. The goal is to perform surgery before rupture occurs.
There are two approaches to surgery. In a traditional (open) repair, a large incision is made in your abdomen and the abnormal section of the aorta is replaced with a graft made of synthetic material, such as Dacron or Teflon. Although safe and remarkably effective, open AAA surgery is a lengthy operation with a long recovery period and may not be feasible in some patients due to associated health problems or advanced age.
The other approach is called endovascular stent grafting. An endovascular stent graft is a tube composed of fabric supported by a metal mesh called a stent. Using a combination of minor surgery and x-ray imaging called angiography, the stent graft is introduced into the inside of the aorta from a small incision in the femoral artery in the groin through the iliac arteries. When deployed, it seals tightly with the normal aorta above and the iliac arteries below the aneurysm. The stent graft excludes the aneurysm from circulating blood by allowing blood flow to pass through it. This prevents the aneurysm from bursting.
Stent grafting has the advantage of being less invasive than open surgery, has shorter convalescence and can be safely done in patients thought to be too sick or old for conventional surgery. The shape and extent of some aneurysms make them unsuitable for this approach.
How do I prevent AAA?
There is no known way to prevent AAA, however treatment before rupture occurs is the best way to prevent death or serious complications. Understanding the risk factors for AAA and regular follow-up with your physician or vascular surgeon to monitor for enlargement and appropriate treatment when indicated is the best way to prevent rupture. In addition, proper treatment of hypertension and stopping smoking may slow the rate of enlargement of AAA. In the future there may be medications available that will be used to slow or retard the enlargement of AAA, however no such medication is currently available. It is known that AAA can occur in families in 10 to 20 percent of cases presumably as an inherited trait, although how this is passed from generation to generation is unknown. As a general rule, if your father, mother, sibling or grandparent has had an AAA, an abdominal ultrasound should be performed periodically once you reach the age of 50 or 55.
Above content provided by Beth Israel Deaconess Medical Center.
For advice about your medical care, consult your doctor.
Posted January 2009
