Should we have a national screening programme to screen for AAA?
When I find myself fixing a burst aneurysm as an emergency in the middle of the night in someone who is desperately ill before I even begin the answer to this seems obvious! If only we had known that the person had an aneurysm before it burst we could have fixed it and prevented it bursting.
AAA are a good subject for screening for several reasons.
- They are an important health problem. It is useful to screen because about 7000 people per year die from ruptured aneurysms in the England and Wales. Many of these deaths could be prevented by a screening programme.
- Aneurysms grow slowly over many years, this gives plenty of time to detect them and treat them if necessary.
- We have a safe and reliable test, an ultrasound scan is inexpensive, reliable and safe.
- We know that it is safe to leave small ones alone and keep an eye on them whereas bigger ones (>5.5cm) should be considered for repair.
- AAA screening meets national cost effectiveness criteria.
A national AAA screening programme has been approved by the government and is gradually being introduced across England.
Men aged 65 will be invited for screening by an ultrasound scan in the community. About 1% will have an AAA that needs fixing, about 4% will have a small AAA that needs watching and about 95% will have a normal aorta and never need to be screened again. Because AAA is much less common in women and occurs in an older age group, there are no plans to screen women.
The graphs show how over time screening reduces the number of emergency operations and the death rate from ruptured aneurysm in places where screening programmes have been introduced. Gloucester was one of the first places in the country to introduce a screening programme. In the graph (Fig 1) you can see how as the years go by following the start of the screening programme the number of emergency repairs (shown in red) comes down. Click here to read article.
In this graph (Fig 2) you can see the result of introducing screening. In the Multicentre Aneurysm Screening Study (MASS), men were divided into two groups, half were offered screening (Red), the other half were not (Control group blue). You can see that as time goes by the number of deaths in the screened group falls. Click here to read article.
In other words screening for AAA, done in the right people at the right time saves lives and is effective.
See also National AAA Screening website.