An aortic aneurysm is a swelling of the aorta, which is the largest artery in the body, the one which exits directly from the heart. This blood vessel, in certain people, can develop a weakened portion within it, which causes the vessel to enlarge over time, like a balloon. If this condition is not detected, the aorta may continue to enlarge until it eventually ruptures, or bursts. This is a dangerous, and often fatal occurrence; most of the time, these people unfortunately do not even make it to the hospital before they expire.
Fortunately, these aneurysms usually grow slowly, about half a centimeter per year, and once detected, there is often time to repair the aneurysm before it bursts.
Aortic aneurysms most often occur in the portion of the aorta within the abdomen; these are called abdominal aortic aneurysms. About 25% of the time, they also involve the portion of the aorta located within the chest or upper abdomen. These aneurysms may also require surgery for repair, and are called thoracoabdominal aneurysms, or thoracic aneurysms, depending on their location.
Unfortunately, aortic aneurysms rarely cause pain, or symptoms until they are about to rupture. They are often silent, causing no pain whatsoever. If an aneurysm is about to rupture, they can cause a throbbing pain in the abdomen or in the back. Once they rupture, they often cause fainting, and severe flank or back pain.
It is not entirely known why aneurysms occur. Certain people are at greater risk for this condition, including those with the following risk factors.
- Age: Abdominal aortic aneurysms occur most often in people age 60 and older.
- Tobacco use: Tobacco use is a strong risk factor for the development of an aortic aneurysm. The longer you've smoked or chewed tobacco, the greater your risk.
- High blood pressure: Increased blood pressure damages the blood vessels in the body, raising your chances of developing an aneurysm.
- Atherosclerosis: Atherosclerosis, the buildup of fat and other substances that can damage the lining of a blood vessel, increases your risk of an aneurysm.
- Being male: Men develop aortic aneurysms five to 10 times more often than women do. However, women with aortic aneurysms have a higher risk of rupture than do men.
- Race: Aortic aneurysms occur more commonly in Caucasians than in other races.
- Family history: People who have a family history of aortic aneurysm are at increased risk of having one. This is especially true if someone in the immediate family had an aneurysm. People who have a family history of aneurysms tend to develop aneurysms at a younger age and are at higher risk of rupture.
It is Because aortic aneurysms do not usually produce symptoms such as pain, they are often diagnosed by "accident," when doctors are looking for other problems (for example, a patient in a minor motor vehicle accident who gets an abdominal CT scan, where the aorta is seen). They are often also diagnosed clinically, when your doctor feels your abdomen. However, since the aorta is located just in front of the spine, it is often hard to feel, and aortic aneurysms can only be detected by physical exam about 50% of the time.
The most common way aneurysms are diagnosed is with an abdominal ultrasound. If this is ordered for you, you will be told not to eat or drink from 9-12 hours before the exam. This is done in order to minimize the amount of gas in the intestines, which can make the ultrasound difficult to read.
If more imaging is needed, a CT scan may be obtained. This shows the aorta in greater detail, and gives exact measurements of the size of the aneurysm. This test also enables the physician to tell which surgical options are available for you.
However, since patients with atherosclerosis are at increased risk, most vascular surgery patients who have multiple risk factors (such as a history of smoking, advanced age, atherosclerosis, family history, etc) will receive an ultrasound to evaluate for this condition.
Also, male patients from the age of 65 to 75 who have ever smoked, are eligible for a one time ultrasound to screen for abdominal aneurysms, as part of the welcome to Medicare Program. Those with a family history of aortic aneurysms or multiple risk factors should also consider obtaining an ultrasound to screen for this disease.
Aortic aneurysms are usually repaired once they reach a certain size, usually 5 centimeters in maximum diameter (a normal aorta is about two centimeters in diameter). However, if a patient knows he or she has an aneurysm and begins to have suspicious abdominal pain, the aneurysm is repaired at that time, even if it is slightly smaller than 5 centimeters.
Treatment for aneurysms is surgery. However, there are two surgical options, including open surgery, and endovascular repair.
In open surgery, an incision is made in the abdomen, and the swollen part of the aorta is replaced by an artificial aorta, which is sewn into place. This artificial aorta is made of a durable woven material. This surgery usually requires several days in the hospital, and can require some time for recovery. There are risks which include (but are not limited to) heart and lung complications such as pneumonia and heart attacks, wound infections, urinary infections, and poor blood supply to the intestines (colonic ischemia). However, in certain patients this is the best option for repairing the blood vessel. After this procedure is finished and recovery is complete, few follow up tests are needed to look at the aorta.
The second option is endovascular repair. This involves a much less invasive surgery, where two small incisions are made in the groin, and a large stent is inserted into the aorta, covering the diseased portion of the vessel, and eliminating the risk of rupture. The recovery is usually much quicker, but there are still risks with every surgery.
Once this procedure is finished, patients will need regular CT scans and/or ultrasounds to make sure the large stent has not moved, and that there is no blood flow within the aortic aneurysm.