Abdominal aortic aneurysm (AAA) screening is a way of detecting a dangerous swelling (aneurysm) of the aorta – the main blood vessel that runs from the heart, down through the abdomen to the rest of the body.
This swelling is far more common in men aged over 65 than it is in women and younger men, so men are invited for screening in the year they turn 65.
An AAA usually causes no symptoms, but if it bursts, it’s extremely dangerous and usually fatal. Around 8 out of 10 people with a ruptured AAA either die before they reach hospital or don’t survive surgery.
Screening involves a simple ultrasound scan of your stomach (abdomen), which takes about 10-15 minutes.
If your abdominal aorta is not enlarged, you don’t ever need to be tested again.
If you have a small to medium aneurysm, you'll be regularly monitored to check it doesn’t get dangerously larger.
If you are found to have a large aneurysm, you'll be seen by a vascular surgeon (a specialist in blood vessels) within two weeks. They will advise on whether you would benefit from treatment to reduce the risk of it bursting.
Why have AAA screening?
An AAA is sometimes picked up by chance – for instance, if you’re being tested for another condition.
In general, if you have an AAA, you won’t know. You probably won’t feel any pain or notice anything different.
But if the aneurysm bursts, it’s a medical emergency, and most people either die before they reach hospital or don’t survive surgery.
Screening is a way of detecting an aneurysm early. If a large aneurysm is detected before it bursts it can be treated. Accepting the invitation to screening cuts the risk of dying from an abdominal aortic aneurysm by about half.
The NHS AAA Screening Programme was set up in England in 2009 and has been offered throughout the UK since the end of 2013.
What happens next depends on the size of your abdominal aorta:
If it’s normal, you won’t ever be invited for another screening. An aneurysm grows so slowly that you’re unlikely to develop one after the age of 65.
If you have a small to medium-sized aneurysm, you’ll be invited back for regular scans to check its size.
If you have a large AAA, you’ll be referred to hospital to be seen by a vascular surgeon within two weeks. You will then be advised about treatment options but, generally, men with a large AAA are advised that the risk of a large aneurysm rupturing is more dangerous than having surgery to repair it.
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Why have abdominal aortic aneurysm screening?
If you have an abdominal aortic aneurysm (AAA), you won’t usually know. You probably won’t feel any pain or notice anything different. Screening is a way of detecting an aneurysm early.
An AAA might be picked up by chance while you are being tested for another problem – for example, if you are given a chest scan because of a persistent cough.
If the abdominal aortic artery gets particularly swollen, you might feel a pulsating feeling or pain in your stomach (abdomen) or back pain.
If you don't experience this, you won’t know you have an aneurysm until it bursts, when it becomes an emergency and is usually fatal. More than 8 out of 10 people with a ruptured AAA either die before they reach hospital or don’t survive emergency surgery.
However, if an aneurysm is found before it ruptures it can be treated – usually by surgery. During this procedure, the swollen section of the aorta is either replaced or strengthened with a section of synthetic tubing.
Because men aged over 65 are particularly at risk of developing an aneurysm, the NHS offers men in this age group screening in order to find aneurysms early, so they can be checked regularly or treated.
The easiest way to find out if you have an aneurysm is to have a screening test, where an ultrasound scan of your abdomen is taken.
The NHS AAA Screening Programme was introduced after research showed it could halve the number of deaths from burst aneurysms among men aged 65 and over.
Who is at risk of an abdominal aortic aneurysm?
Men are approximately six times more likely to have an abdominal aortic aneurysm than women. The chance of having an aneurysm increases with age.
The risk of having an abdominal aortic aneurysm can also increase if:
you have high blood pressure
a brother, sister or parent has, or has had, an abdominal aortic aneurysm
Screening is a choice and all screening involves a balance of potential harms, as well as benefits.
The UK research study, which was set up to find out whether a national AAA screening programme would be worthwhile, has now been running for over 10 years, and shows that it will cut the risk of dying from an AAA by 48% in men over the age of 65.
There is no risk from the scan itself. However, if you find out from the scan that you have a large aneurysm, it could lead to difficult decisions about having surgery, which has its own risks.
Being told you have a life-threatening condition can also cause considerable anxiety.
It’s important to consider all the information carefully, and you will be sent an information leaflet with your screening letter to help you make this decision.
When abdominal aortic aneurysm screening is offered
The risk of dying from a ruptured abdominal aortic aneurysm (AAA) is greatest in men aged over 65. This is why the NHS AAA Screening Programme offers screening to men aged 65 and over.
Men are invited for screening during the year they turn 65 (April 1 to March 31). This means you’ll either be invited when you’re 64 or just after your 65th birthday.
If you’re registered with a GP, you will receive a letter from the NHS AAA Screening Programme inviting you for an appointment at a local screening clinic, which might be at your own GP surgery. If you don’t respond to this first invitation, you will be sent a second invitation within six weeks.
Women and younger men are not invited for screening because 95% of ruptured AAAs occur in men aged 65 and over.
Men are six times more likely to have an AAA than women, and the chance of having an aneurysm increases with age.
All the risks and benefits are carefully studied before a new screening programme is introduced. This is to ensure that the benefits of being offered screening outweigh any potential harms.
The UK National Screening Committee reviewed scientific evidence from around the world and concluded that there is not enough evidence of the benefits of offering screening to women over 65 and younger men.
What if my family has a history of AAA?
Your risk of developing an AAA increases if you have a close family member – brother, sister or parent – who has an AAA or died from one.
If you have, speak to your GP about the possibility of being referred for a scan.
The usual advice is to have a scan when you’re five years younger than your relative was when the AAA was found.
Close relatives of someone with an AAA should take the usual health precautions of not smoking, having a cholesterol and blood pressure check, and staying as healthy as possible.
If the scan shows you have an AAA that is 5.5cm or larger, you will be referred to a vascular surgeon (a surgeon who specialises in diseases of the blood vessels), who may recommend an operation.
You should be seen by the surgeon within two weeks of your screening appointment.
The surgeon will discuss treatment options with you, taking into account your general health and fitness, as well as the size of your AAA.
There are two main options for surgery, which are:
open surgery – where the surgeon cuts into your stomach (abdomen) to reach the abdominal aorta and replace the enlarged section with a synthetic tube called a graft
endovascular surgery – a type of "keyhole" surgery where the surgeon makes small cuts in your groin and guides the graft through a leg artery up into the swollen section of aorta to reinforce the wall
If you’re not fit or well enough to undergo surgery, or you don’t want to have surgery, you will be offered lifestyle advice and possibly medication. This can help slow down the growth of an AAA and reduce the risk of a rupture.
Read detailed information about treating a large AAA, including the advantages and disadvantages of different types of surgery.
the DVLA must be informed if the aneurysm grows to 6cm
the person's licence will be suspended if their aneurysm grows to 6.5cm
their licence will be reinstated after their aneurysm has been successfully treated
The policy on bus, coach and lorry drivers states that:
the DVLA must be informed if they have an aneurysm of any size
the person's licence will be suspended if their aneurysm grows to 5.5cm
the person's licence will be reinstated after their aneurysm has been successfully treated
The screening programme refers men to vascular surgeons if their aneurysm reaches 5.5cm.
The DVLA policy does not affect car drivers with small or medium aneurysms (3.0-5.4cm) who are part of the programme's surveillance group.
6. What are the implications for air travel and travel insurance?
The Association of British Insurers (ABI) has been advised that AAAs are no more likely to rupture at altitude than on the ground, and it is not aware of any airlines operating a standing rule about refusing patients with this condition.
The ABI is also unaware of any travel insurance policies that contain a specific exclusion for AAAs as part of their standard wording.
If an applicant for travel insurance declares an AAA, the ABI understands that the medical screening process does not ask the diameter of the aneurysm, because to do so would be to expect a degree of medical knowledge on the part of the patient that they might not have.
Patients are instead asked whether or not they have had definitive treatment, such as surgery, and if so, when. They are also asked if they are on a waiting list for such treatment and if they have any other related cardiovascular diseases.
The ABI suggests that anyone with an AAA should declare the condition during the travel insurance application process, or when it has been diagnosed, if they have an existing travel policy.
Where an applicant declares an AAA, they may be charged an additional premium or have the condition excluded from cover.
7. What permission do I need to give to be screened?
At the screening clinic, you will be asked to give your permission:
for the programme to store and keep information about you and your visit on the national AAA screening IT system, and to use this information to help offer safe and effective screening
for the programme to screen you for an AAA (which involves an ultrasound scan of your abdomen) and to inform you of the result
if you are found to have an AAA, to share your personal information with a vascular surgeon through the National Vascular Registry
Men will only be screened if they give their consent to all three of the points above.
You will also be asked if the NHS AAA Screening Programme can use your information to contact you in the future to let you know about research that is going on in the programme. You do not have to give permission for this to be screened.
8. Why do I need to give permission for the programme to keep my personal information if I want to be screened? How is my personal information stored?
Screening is a diagnostic procedure that requires the person’s consent. There is an associated duty of care to record information to provide evidence of what is done, what is found, and to share this with appropriate healthcare providers, so any findings can be followed up.
Recording data enables the programme to ensure that screening, assessment and treatment are effective and timely.
The abdominal scan is only one part of a systematic pathway of care. It would be irresponsible and potentially negligent to offer a scan without ensuring that the safeguards offered by an assured national system are in place.
The screening programme needs to retain personal data so it knows if and when a man has been scanned, and if he has declined screening.
It also allows local programmes to keep track of who has, or has not, been invited for screening and deal with follow-up enquiries.
Personal information is only available to healthcare professionals involved in an individual man's screening or any subsequent assessment or treatment.
The programme controls and processes personal information in a manner that is compatible with the Data Protection Act (the data controller). The programme uses a third party (Northgate Public Services) to process and manage this personal information in a secure database.
Although the database is a national system, strict data governance means that personal details can only be accessed by staff involved directly in an individual man's screening process.
If a man is screened and found to have an aneurysm, it will be necessary to share his information with a vascular unit to support further investigation and potential surgery.
Men may decide, after they have been invited or attended screening, that they do not want the NHS AAA Screening Programme to contact them again in the future or provide any ongoing care for them – either directly, or via any other healthcare professional. Men who ask to be removed from the screening invitation or recall process will be given information about the risks of their decision.
Requests for removal must be made in writing to their local screening unit. Men can subsequently request to be reinstated into the screening invitation and recall process at any time.
9. What happens if I give my permission to be contacted about research in the NHS AAA Screening Programme?
The NHS AAA Screening Programme works closely with medical researchers to improve screening and the care of men being screened for AAA and men with AAAs. If men give permission for the programme to contact them about research, they may be sent information about ongoing research and how they can get involved, if they wish to do so.
All involvement in NHS research is optional. The decision to participate in research or not does not affect the care men receive from the NHS.
Men who give their permission to be contacted about research will be able to decide whether to participate on a project-by-project basis.
The programme does not pass any personal information on to medical researchers directly. All research projects must first be approved by the NHS AAA Screening Programme Research Committee.
10. Does the programme do anything else with the personal information it keeps?
The programme has an obligation to monitor its own performance and determine if it can be improved or refined. This ensures the service is of good quality and achieving its main aim of preventing men dying from the complications of having an aneurysm.
One of the ways the programme measures performance is by monitoring what happens to men who have been invited for screening. It does this by obtaining information for men invited for screening from the Health and Social Care Information Centre (HSCIC).
This information is either held by the HSCIC directly (data on hospital admissions, which is collected from all NHS Hospitals) or obtained from other government organisations (data on deaths are held by the Office for National Statistics).
To ensure confidentiality, the programme anonymises the data by removing information such as men's names and dates of birth. It only passes NHS numbers on to the HSCIC, which it uses to link to health records. The HSCIC matches the information provided with the information it holds and, again, removes all identifiable information, including NHS numbers.
Anonymous data from the programme and the HSCIC is then passed to the University of Leicester, the programme’s current academic partner. The University of Leicester analyses this information and provides the programme with a report on its performance. At no point will an individual man's identity be known to the analysis team at the University of Leicester. All data is held securely at the University of Leicester and is not made available to any other parties at any time.
The data resulting from this process will be held for a maximum of 20 years. This is because aneurysms develop very slowly and it takes a long time to properly assess the full benefits of the screening programme. If you do not want your anonymised healthcare data used in this way, then please contact your local screening service.
11. Could I find out about other health problems as a result of AAA screening?
No, during the ultrasound scan (the screening test), the technician only looks at your aorta specifically to check if you have an AAA.
If you have any concerns about your health, speak to your GP.
12. Where can health professionals find out more about the AAA screening programme?