Abdominal aortic aneurysm
An abdominal aortic aneurysm is an enlarged area in the aorta which supplies blood and runs from the heart through the chest and abdomen. Should an aortic aneurysm burst, it can cause life-threatening bleeding.
Definition & Facts
An aortic aneurysm occurs when the walls of the aorta bulge or dilate. Most abdominal aortic aneurysms occur near the navel, although they may occur in other areas. Abdominal aortic aneurysms are not related to brain aneurysms. Abdominal aortic aneurysms are rare in people under the age of 60 and the risk of an aortic aneurysm rises after the age of 65. Almost 90 percent of aneurysms are small and unlikely to cause significant problems.
Symptoms & Complaints
Often, the pain is caused by the aneurysm growing larger which may indicate a heightened risk of rupture. Blood clots can also form in the aneurysm which may break loose and clog blood vessels in the leg. When this occurs, a patient may report pain, numbness, or tingling. The patient’s foot may also turn pale and feel cool when touched if a blood clot from an aneurysm breaks loose. There is often no warning before an abdominal aortic aneurysm ruptures.
Although an abdominal aortic aneurysm may have no causes, there are factors that may increase someone’s risk of developing one. Smoking is one of the most common causes of aortic aneurysms, with the risk increasing with each year the patients smokes and decreasing each year after they stop smoking. Men are also about five times more likely to develop an aortic aneurysm than women while white people are also at higher risk than other ethnicities.
A diagnosis of coronary artery disease or peripheral artery disease may also increase the risk of developing an abdominal aortic aneurysm. Family history is another factor that increases the risk of an aortic aneurysm. The brother of a patient who suffers from the condition is 18 percent more likely to develop one as well.
Diagnosis & Tests
The most common test used to diagnose an abdominal aortic aneurysm is an abdominal ultrasonography. During the test, a wand is placed on the abdomen and high frequency waves create an image of the aorta. If an aneurysm is present, it is visible in the image.
Men who are 65 to 75 who have never smoked should be screened once using the test and no additional tests are recommended if the initial test is negative. Men who have a family member, especially a parent or sibling, who has been diagnosed with an abdominal aortic aneurysm should receive the screening at age 60.
There is no recommendation for screenings for women, but those that have family members who have been diagnosed with an aortic aneurysm should discuss their risks with their doctor. Although the risk of developing the condition is lower for women, the risk of rupture is higher for women than for men.
Treatment & Therapy
The goal of treatment for an abdominal aortic aneurysm is to prevent rupture as success rate of surgery is significantly lower after a rupture. As many as 15,000 people die each year due to a ruptured abdominal aortic aneurysm. For aneurysms that are at low risk of rupture, most physicians simply monitor the situation closely, only taking steps to correct the problem if it appears the aneurysm has grown larger.
For those who are being monitored, the doctor will take steps to control blood pressure carefully and the patient should stop smoking immediately. A beta blocker may be recommended as research has indicated that such medications slow the rate of aneurysm growth. The patient should also increase physical activity, such as biking or walking, but should not perform heavy lifting or exercises that cause strain. If any abdominal tenderness or back pain develops, patients should contact their doctor immediately.
In the case of a patient with an abdominal aortic aneurysm that may rupture, the doctor may recommend surgical repair, and there are two options available. Surgery is recommended if the aneurysm is causing symptoms, is larger than 5.5 cm (2.2 inches) in diameter, is expanding or the patient also suffers from other aneurysms in the iliac artery, femoral artery, or popliteal artery.
One type of surgery, known as open repair surgery, involves removing the section of the abdominal aorta affected and replacing it with a graft, which is a prosthesis made of synthetic material and which allows blood to flow normally. The arterial wall covers the graft and failure of the graft is uncommon. However, there are risks, especially among smokers or patients with other types of cardiovascular disease, including irregular heart rate and stroke, as well as pneumonia.
It is also possible that repair will be performed using an endovascular stent graft which is much less invasive than open surgery. In this procedure, an incision is made in the groin, and a wire is placed in the femoral artery in order to guide a catheter with a folded graft to the aneurysm where it is unfolded and expanded with a balloon. Unlike open surgery, the graft is not stitched in place.
Prevention & Prophylaxis
Patients who undergo surgery for an abdominal aortic aneurysm may take up to six weeks to recover if they choose open surgery while endovascular stent graft recovery may take approximately two weeks.