Treatment for an abdominal aortic aneurysm (AAA) depends on several factors, including the aneurysm's size, your age and general health.

In general, if you have a large aneurysm (5.5cm or larger) you will be advised to have surgery, either to strengthen the swollen section of the aorta or to replace it with a piece of synthetic tubing.

This is because the risk of the aneurysm rupturing is usually greater than the risk of having it repaired. 

If you have a small (3.0-4.4cm) or medium (4.5-5.4cm) aneurysm, you will be offered regular scans to check its size.

You will also be given advice on how to slow its growth and reduce the risk of it rupturing – for example, stopping smoking – and perhaps medications to reduce your blood pressure and cholesterol level.

If you have a large AAA

If you are diagnosed with 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.

The surgeon will discuss treatment options with you, taking into account your general health and fitness, as well as the size of your aneurysm.

If it's decided that surgery isn’t suitable for you, it’s still possible to reduce the risk of the aneurysm bursting, and you will have regular scans to check its size – in the same way people with small or medium aneurysms are treated.

See below for more information on treating small and medium aneurysms.

There are two surgical techniques used to treat a large aneurysm:

• endovascular surgery
• open surgery

Although both techniques are equally effective at reducing the risk of the aneurysm bursting, each has its own advantages and disadvantages.

The surgeon will discuss with you which is most suitable.

Endovascular surgery

Endovascular surgery is a type of "keyhole" surgery where the surgeon makes small cuts in your groin.

A small piece of tubing called a graft– made of metal mesh lined with fabric – is then guided up through the leg artery, into the swollen section of aorta, and sealed to the wall of the aorta at both ends.

This reinforces the aorta, reducing the risk of it bursting.

This is the safest of the two types of surgery available. Around 98-99% of patients make a full recovery, and recovery time from the operation is shorter than if you have open surgery.

There are also fewer major complications, such as wound infection or deep vein thrombosis (DVT). 

However, the way the graft is attached is not as secure as open surgery. You’ll need regular scans to make sure the graft hasn’t slipped, and in some patients, the seal at each end of the graft starts to leak and will need to be resealed. You will need to have surgery again if either of these occurs.

Open surgery

In open surgery, the surgeon cuts into your stomach (abdomen) to reach the abdominal aorta and replaces the enlarged section with a graft.

This type of graft is a tube made of a synthetic material.

Because the graft is stitched (sutured) into place by the surgeon, it’s more likely to stay in place, and will usually work well for the rest of your life.

The risk of complications linked to the graft after surgery is lower than in people who have endovascular surgery.

Open surgery isn’t usually recommended for people who are in poor health as it is a major operation. It is slightly more risky than endovascular surgery, with 93-97% of patients making a full recovery.

The main risk of open surgery is death or heart attack, and recovery time is longer than with endovascular surgery.

There is also a greater risk of complications, such as wound infection, chest infection and DVT.

Making a decision about treatment for a large aneurysm

If you or a relative is faced with making a decision about treatment for a large AAA, the AAA repair decision aid may help you weigh up the pros and cons of each option.

If you have a small or medium AAA

If you are diagnosed with a small (3.0-4.4cm) or medium (4.5-5.4cm) aneurysm, you won’t be referred to see a vascular surgeon, as it’s unlikely you’d benefit from surgery.

You’ll be invited back for regular scans to check the size of the aneurysm, in case it gets bigger – every year if you have a small aneurysm and every three months if you have a medium aneurysm.

You will also be given advice on how to prevent the aneurysm from getting bigger, including:

• stopping smoking
• eating a balanced diet
• ensuring you maintain a healthy weight
• taking regular exercise

If you smoke, the most important change you can make is to quit. Aneurysms have been shown to grow faster in smokers than in non-smokers.

Read more about stopping smoking and nicotine replacement therapies (NRTs) that can make it easier to stop smoking.

Your GP will be sent your test result and may decide to change your current medication or start you on a new one, especially if you have:

• high blood pressure – which you will probably be treated for with a medication called an angiotensin-converting enzyme (ACE) inhibitor
• high cholesterol – which you will probably be treated for with a medication called a statin

Treating a ruptured AAA

Emergency treatment for a ruptured AAA is based on the same principle as preventative treatment. Grafts are used to repair the ruptured aneurysm.

The decision on whether to perform open or endovascular surgery is made on a case-by-case basis by the surgeon carrying out the operation.