Abdominal Aortic Aneurysm (AAA) Screening

An Abdominal Aortic Aneurysm is a swelling in the aorta, which happens due to the weakening of the artery walls with age. If not spotted or left untreated it can become too large and rupture, which will cause internal bleeding. The AAA screening programme was introduced in 2008 and fully rolled out by 2013, and aims to detect an AAA before it poses a risk. Evidence shows screening can halve the risk of dying from a ruptured AAA. Generally, an AAA will produce no symptoms, so attending routine screening is the best way to detect one.

Men aged 65 and over are most at risk of developing an AAA; they are 6 times more likely to have one than women of the same age. There is no current evidence to suggest that screening women or men younger than 65 would have any benefit. It is estimated that 1.34% (1 in 92) men in England and Wales aged 65+ have an AAA, and that ruptured AAA’s cause 5000 deaths a year, contributing to 1.7% of overall deaths in this population. If an aneurysm ruptures, the chances of death before reaching a hospital are approximately 85%.

The screening invitation

Each year around November, the screening programme receives information from all the GP’s they serve on which of their male patients will be turning 65 during the next cohort year, which runs from the beginning of April to the end of March. The programme then sends these men a letter with a screening appointment date and time, at a clinic site local to their GP. Transgender and non-binary people will be automatically invited if they are registered male with their GP. Those who are assigned male at birth but registered as female will not be invited but are still at a higher risk so should speak to their doctor if they wish to be screened. Men under 65 and women of any age who have a family history of AAA can also request screening by speaking to their doctor. Men over 65 who have never been screened can self-refer by calling their screening team.

The screening appointment

Screening involves an ultrasound of the stomach, which takes around 10 minutes. The technician will give the results straight away, unless the images are unclear in which case the man will be invited back to be screened on a different day. If an AAA is found, a letter with the results in will be sent to their GP and to the patient’s home address with all the necessary information in. Longer appointments can be made for those with additional needs – GP’s will be asked for this information by the screening service via a prior notification letter, or the patient themselves can call in advance to request one. The screening service can also book an interpreter for those that require one.

Men who do not attend will be automatically be sent a second appointment, usually within a couple of months of the first. A second non-attendance will result in them being excluded from the service, so they will not receive any more appointments and will have to self-refer if they would like to be screened. Appointments can be changed if not suitable, and men are able to defer screening for any length of time if they wish. If they do not want to be screened, their screening team can exclude them from the service permanently.

Results and outcomes

Result Size Incidence Outcome

No AAA < 3cm Most men No further treatment – discharged

Small 3cm – 4.4cm Just over 1% Invited back for yearly scans

Medium 4.5cm – 5.4cm 0.5% Invited back for 3-monthly scans

Large 5.5cm or more 0.1% Referred to a vascular surgeon within 2 weeks

Small and medium AAA’s grow very slowly, so men will be invited back for regular screenings to monitor its size. They will also be given lifestyle advice on how to help reduce the risk of the AAA growing, such as stopping smoking, eating healthier and exercising regularly. Medication may also be advised to help reduce blood pressure and cholesterol. Large AAA’s have a higher risk of bursting so the patient will be referred to a specialist, usually within 2 weeks of their screening appointment, to discuss surgery to repair it.

Risk factors

- Male and aged 65 or over

- Smoker/ex-smoker

- High cholesterol

- High blood pressure

- Family member with an AAA

- Atherosclerosis

- COPD

- Diabetes

- Certain other health conditions (e.g. Marfan syndrome)

Commonly asked questions

Where will I get screened?

You will be invited to a clinic that is close to you. If you need to change your appointment or want to delay your screening for a later time, you can speak to your screening team using the number on your letter. If you are struggling to attend your appointment from a different reason, please call your screening team who will try their best to help you.

Do I have to get screened?

No – screening is your choice. When you receive your letter you will get a booklet outlining all the information you need to decide. If you don’t want to be screened, you can tell your screening team who will remove you from their list and not contact you again. If you change your mind in the future, you can then self-refer.

What if I missed my appointment?

If you missed your appointment for whatever reason, you will automatically be sent a second appointment. If you miss this one, you won’t receive any more, but can still book one in the future by calling the screening service.

Why is the programme just for men?

Men are 6 times more likely to have an AAA than women, which is why the national programme currently only invites men. Women who have a family history of AAA can request to be screened by asking their GP for a referral, due to the genetic risk factor.

Do I need to come back again if I don’t have an AAA?

No – if no AAA is found then that will be your only screening. This is because an AAA grows so slowly, that the chances of you developing one and it becoming large enough for treatment are very small.