Why are men offered screening for abdominal aortic aneurysms?

In the screening examination, ultrasound is used to measure the diameter (width) of the abdominal aorta. The next steps are determined by the results of this measurement.

If 1,000 men aged 65 and over are screened, we can expect the following results:

• About 980 of the 1,000 men will not have an aneurysm: Their aortas will all have a diameter of less than 3 cm (1.18 inches). This is considered to be a "normal" size.
• About 18 of the 1,000 men will have a small to medium-sized aneurysm: If the abdominal aorta is 3 to 5.4 cm (1.18 to 2.12 inches) in diameter, experts recommend that it is monitored regularly using ultrasound. If it gets bigger, surgery may be a good idea later on.
• About 2 of the 1,000 men will have a large aneurysm: If the diameter is 5.5 cm (2.16 inches) or more, the risk of rupture is relatively high. Surgery is usually recommended in these cases.

The following illustration shows the expected results of screening described above.

But

• even if the results are normal, an aneurysm may still develop later on.
• Some of the aneurysms that are discovered would never have caused any health problems.

Especially if the aneurysm is large, there is a risk that it will unexpectedly rupture within the next few years. Screening can help to prevent a rupture that causes life-threatening blood loss.

Studies have looked into how many ruptures and deaths can be avoided by detecting aneurysms early on. The following estimate shows what men aged 65 and over can generally expect during the 13 years following screening with ultrasound:

Some of the aneurysms found during the scan would have gone unnoticed if it hadn't been for the screening. They wouldn't have ruptured, and check-ups or surgery wouldn't have been necessary. Unfortunately, it's not always possible to tell the difference between harmless aneurysms and dangerous ones.

It is estimated that about half of the aneurysms that are found remain harmless – particularly the small aneurysms. In other words,

about 20 out of the 1,000 men who have screening find out that they have an aneurysm. But the aneurysm would never have caused any trouble in about 10 of them.

The diagnosis can stir up very different and sometimes mixed emotions. Some men are glad that their aneurysm was discovered – the check-ups make them feel safe.

Other men wish they hadn't found out about it. Knowing about it can be scary and worrying.

Many men go on living with the feeling that their lives are in danger. Things like abdominal pain can then be unsettling. And many men stop doing certain things in everyday life out of fear that the aneurysm could rupture. They become more cautious and avoid physical exertion.

If a large aneurysm is discovered during a screening examination, surgery could be an option. Preventive surgery can be done in two ways:

• The aneurysm is opened and replaced with an artificial blood vessel. To do this, the surgeon needs to cut through the wall of the abdomen (belly).
• A tube is implanted in the aneurysm. This procedure involves making a small cut in the groin. The tube is inserted through the cut and into the aorta using a catheter, and pushed through to where the aneurysm is.

Both of these procedures can save lives. But they can also cause serious complications, such as a heart attack, a stroke, a lung infection, or an infection of the artificial blood vessel or nearby tissue.

So it's important to carefully consider whether the risk of the aneurysm rupturing is big enough to justify having surgery. The decision about whether or not to have surgery will also depend on the man's general health and how he views the pros and cons of surgery himself.

Different men draw different conclusions about the pros and cons of screening. Some want to have screening because they consider it to have more benefits, whereas others decide against it because they see more drawbacks. A decision aid may help you to figure out how you feel about the pros and cons of screening for an abdominal aortic aneurysm. It can help you to determine what is important to you and what you would like to know more about. It can also be useful when preparing to have a talk with the doctor.