Aortic aneurysm

The aorta is the main artery that carries blood from the heart down through the chest and abdomen. An abdominal aortic aneurysm (AAA) is a weakened section of its wall in the abdomen that has stretched and widened, like a balloon.

Most aneurysms grow slowly and cause no symptoms at all. They are usually found by chance on an ultrasound or CT scan done for another reason, or through screening.

They matter because a large aneurysm can burst (rupture), causing severe internal bleeding that is often fatal. The risk of rupture rises as the aneurysm gets bigger. The aim of care is to watch small aneurysms safely and repair larger ones before they cause harm.

An aneurysm develops when the wall of the aorta weakens over time. The main risk factors are:

Smoking, now or in the past, which is the most important one

Being male and over 65

A parent, brother or sister who had an aneurysm

High blood pressure

Other artery disease, such as heart disease or narrowed leg arteries

High cholesterol

Women get aneurysms less often, but when they do, the aneurysm may be more likely to rupture at a smaller size. Because aneurysms are silent, many guidelines recommend a one-off ultrasound check for men around 65, and for others at higher risk, such as those with a strong family history.

The first test is usually an abdominal ultrasound. It is quick, painless, uses no radiation and measures the width of the aorta accurately. A normal abdominal aorta is about 2 cm wide; an aorta of 3 cm or more is called an aneurysm.

If the aneurysm is large or repair is being considered, a CT angiogram (a CT scan with dye) shows its exact shape and length and whether a stent-graft is suitable.

At the visit, the doctor also reviews your heart, lungs, kidneys and blood pressure, as these affect the choice and timing of treatment. For an abdominal ultrasound you may be asked not to eat for a few hours beforehand, so less gas is in the bowel. Bring all previous scans and reports, as comparing sizes over time is important.

Treatment depends mainly on the size of the aneurysm, how fast it is growing and whether it causes symptoms:

Ultrasound surveillance: small aneurysms are measured regularly, from yearly to every few months as they grow. The risk of rupture from a small aneurysm is low, and surveillance is the safest plan.

Risk-factor control: stopping smoking, controlling blood pressure, and usually a statin and an antiplatelet to protect the heart and arteries.

EVAR stent-graft: once an aneurysm reaches the size for repair, often around 5.5 cm in men and a little smaller in women, or grows quickly, a fabric-covered stent is placed inside it through the groin arteries. Blood then flows through the graft, taking pressure off the weak wall.

Open repair: through a cut in the abdomen, the aneurysm is replaced with a synthetic tube. It is a bigger operation but may suit some aneurysm shapes and younger, fitter patients better.

After EVAR, most patients stay in hospital for one or two nights and return to normal daily activities within a week or two. Avoid heavy lifting while the groin punctures heal.

After open repair, the hospital stay is longer, usually about a week, and full recovery takes several weeks to a few months.

Follow-up is essential. After EVAR you will need scans for life, usually ultrasound and sometimes CT, to check that the stent-graft stays in place and that no blood is leaking back into the aneurysm sac (an endoleak). Most problems found this way can be treated with another minor procedure. Whatever the treatment, keep taking your heart and blood pressure medicines and stay off cigarettes.

Book a visit if a scan has shown a widened aorta, if you are a man around 65 who has smoked, or if a close relative had an aortic aneurysm. Also book if you feel a pulsating lump in your abdomen.

See a doctor urgently, the same day, if you have a known aneurysm and develop:

New pain in the abdomen, back or side that does not settle

Tenderness over the aneurysm

Call an ambulance straight away if you have:

Sudden, severe pain in the abdomen or back, sometimes spreading to the groin or legs

Fainting, dizziness, sweating or a racing heart

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These can be signs of a rupture, which needs emergency surgery. Tell the paramedics you have an aneurysm, if you know about it.