What is 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 and into abdomen. The abdominal aorta supplies blood to the lower part of the body. Just below the abdomen, the aorta divides into two branches that 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.
When aneurysms become very large (bigger than 5.5cm or about 2 inches), they may burst, or rupture. Once an anuerysm reaches that size, then surgery is usually recommended. However, smaller aneurysms rarely burst and, in many cases, never grow to a size where they are likely to give rise to problems. For this reason, if your aneurysm is small (less than 5.5cm) it may be safest for you to have your aneurysm monitored by regular scans as you may completely avoid the need for a surgical procedure.
How will it be monitored?
It is not easy to determine the size of an aneurysm by examining the abdomen and a scan is required. Usually, an ultrasound scan will allow us visualise the aorta to determine the size. This is performed in the vascular laboratory. No anaesthetic or special preparation is required. The scan is painless and takes only a few minutes. During the scan, the technologist will press an ultrasound probe on the abdomen.This test is usually repeated at six monthly intervals but your doctor will discuss the precise timing of each scan with you after the test.
In some cases, a CT scan is required. This will be perfomed in the radiology department and usually requires an intravenous injection. The scan itself is painless and also only takes a few minutes.
What happens if the aneurysm grows larger?
If the aneurysm grows bigger than 5.5cm, surgery is usually required. This may be perfomed using keyhole technology in some cases (please see our EVAR leaflet) or using conventional open surgery (Please see our Open AAA repair leaflet).
What should I watch out for?
In the vast majority of cases, smaller aneurysms cause no symptoms or problems. However, should you develop sudden severe abdominal or back pain, then you should attend immediately (to the Emergency department) to have your aneurysm checked.