Treatment of thoracic aortic aneurysm (TAA)

What is a thoracic aortic aneurysm?

The aorta is the largest blood vessel in the body. It carries blood from the heart through the chest and the abdomen (tummy). At around the level of the belly button the aorta divides into two iliac arteries carrying blood to each leg.

An aneurysm develops when the wall of a blood vessel becomes less elastic and starts to ‘balloon’, this makes the wall weaker and at risk of bursting (rupture).

Aneurysms can occur in any artery. They most commonly occur in the section of the aorta that passes through the abdomen. This is known as abdominal aortic aneurysm (AAA). The next most common place for an aneurysm is in the aorta in the chest, thoracic aortic aneurysm (TAA).

What should I be concerned about?

The major concern is that an aneurysm will burst (rupture). This happens because the wall of an aneurysm is weaker than that of a normal artery.

If an aneurysm bursts this causes internal bleeding. This is usually a sudden event, with little or no warning, and one that most people do not survive.

How does an aneurysm affect my life?

We advise maintaining a low blood pressure and no heavy lifting or high-intensity exercise, otherwise you should continue to live and work as normal. If you do have a heavy manual job, please discuss with your consultant any concerns you might have.

You can still drive, unless you are given instruction by your consultant not to (e.g. if your aneurysm is very large, bigger than 6.5cm in diameter) or you are an HGV driver. If you drive, you must inform the DVLA:

What is the risk of TAA rupture?

The risk of aneurysm rupture increases with aneurysm size (page 9). Usually the benefits and risks of intervention are considered when the aneurysm is bigger than 6cm across. Sometimes interventions are considered for a smaller aneurysm if you are female or if you have Marfan syndrome (or another connective tissue disorder).

The risk of TAA rupture is greater in:

  • Women
  • People who smoke
  • People with a family history of aortic aneurysm or dissection
  • People with uncontrolled high blood pressure
  • People with chronic chest problems (COPD)

If you develop severe chest or back pain, then you should call 999 to be taken to your nearest Emergency Department for assessment.

Should everyone with a TAA have surgery?

The short answer is no, as each person’s risk of rupture and risk of complications from surgery is different. The decision of whether to choose to undergo treatment for TAA is a balance. Some people, after discussing treatment options with their surgeon, choose to ‘do nothing’ for their aneurysm, as the treatment risk exceeds the benefit.

Examples of balancing the benefits and the risks:

Shared decision in favour of ‘do nothing’

A man is aged 75 years old and has a 5.5cm TAA which cannot be treated by a standard endovascular stent. He gets daily chest pain (angina) and has had a stroke. He is at very high risk of a major complication from surgery which in turn, would make a reduced life expectancy more likely.

Risk of surgery increases, as:

  • Higher risk of death or complications
  • Recent stroke
  • Chest pains

Risk of rupture decreases, as:

  • TAA is 5.5cm so 5% risk of rupture per year

Shared decision in favour of choosing surgery

Now, let us take a 67-year-old man who, two years after a heart bypass operation for angina, has been found to have a 6.5cm TAA. He has surgery and no longer gets chest pains.

Risk of surgery decreases, as:

  • Average surgical risk
  • Previous heart operation but no problems since

Risk of rupture increases, as:

  • TAA is 6.5cm so 10% risk of rupture per year

Will I need special tests?

The type of surgery you need, and the risks associated with that surgery, depend in part on the shape of your aorta and the relationship between the dissection and branches from the aorta that supply your head, arms, liver, intestines, kidneys, pelvis and legs.

The aneurysm is evaluated using a CT scan. For example, the image shows a thoracic aortic aneurysm, with a ‘saccular’ element close to the aortic arch and ‘fusiform’ segment in the mid descending aorta. This aneurysm can be treated by either open surgery or an aortic stent graft (EVAR).

You will also have assessments of your fitness:

  • Consultation with a doctor with a specialist interest in medicine for the elderly (complex care assessment, CCA)
  • Stationary bike test (cardiopulmonary exercise test, CPET)
  • Pre-operative assessment clinic appointment (POAC)

More information about preparation for surgery can be found in the leaflet, ‘Coming in for your aortic surgery’.

Screening family members

In up to 50% of people developing a TAA is thought to be inherited. Your vascular specialist will ask you about your family history. If you have close relatives with AAA, TAA, or aortic dissection, you may want to consider having genetic testing.

Your vascular specialist may also recommend imaging of family members with ECHO or MRA to check if they have aortic disease.

Your treatment options

Open surgical repair

Open surgical repair involves opening your chest (a thoracotomy) to repair the aneurysm by sewing in an artificial piece of artery (graft), shown in the image.

This is major surgery and requires your surgeon to stop the blood flowing in the aorta with clamps for a period whilst the graft is stitched into place. This may need a heart bypass.

Your vascular specialist may recommend that the risks of open surgery are too great to contemplate. This recommendation will depend on factors including your age, health and the shape of your aneurysm. If you have an aneurysm which extends up to your aortic arch or down to your abdomen, surgery will be technically more difficult. The risk of death or a major complication will as a result be higher. More detailed information on open arch and thoracic aortic surgery can be obtained from the Bristol Heart Institute.

  • ’Frozen elephant trunk’ (‘Thoraflex’ or ‘FET’) for treating aneurysm involving the aortic arch.
  • Open thoraco-abdominal aortic aneurysm repair (thoracic and abdominal).

Aortic stent graft (TEVAR)

A stent graft consists of synthetic fabric tubes (the ‘graft’) mounted onto metal skeletons (the ‘stents’).

The stent graft comes loaded into a delivery system. The delivery system, of similar width to a pen, is small enough to be inserted through an artery in your groin. The stent graft is positioned using X-rays and deployed using the delivery system, which is then removed and the small incisions in the groin closed.

The aim of the stent graft is to allow blood to only flow through the stent graft tubes and not into the bulging sac of the TAA.

The sac is no longer under pressure and should shrink with time. In this way, we ‘exclude’ the AAA and reduce the risk of it rupturing.

Please read our ‘Thoracic aortic stent graft’ leaflet for more details. You can also watch video animations of how the thoracic stent grafts work here:…

Complex aortic stent graft (complex EVAR)

In some people, the shape of their AAA is such that there is insufficient healthy aorta below the arteries to the kidneys, or in one or both common iliac arteries, for a standard stent graft to fix in place. To treat these aneurysms, it is often possible to use a ‘complex’ stent graft, often custom made to fit an individual patient.

Instead of being a ‘tube,’ custom stent grafts are made with holes (fenestrations) or branches, in the positions that arteries come off the aorta and/or for the internal iliac arteries. These maintain blood supply to vital organs, or the pelvis, whilst excluding the aneurysm sac from blood flow.

The stent graft is completed with components as for a standard endovascular repair. This means that these ‘complex’ stent grafts can be safely extended up into the thoracic aorta or down into the external iliac arteries.

Complex aortic stent grafts carry higher risks than standard EVAR. There is also a higher risk of needing further procedures. However, complex stent grafts are significantly safer than open surgery when a clamp must be placed above the arteries to the liver and gut – for aneurysms that extend up into the chest.

Please read our ‘Complex Aortic Stent Grafts’ leaflet for more details.

Do nothing (medical management)

Some people decide that they simply do not want aortic surgery.

‘Doing nothing’ means a shared decision between you and your vascular surgeon that the best option for YOUR aneurysm is to leave it untreated. This decision is usually made when the risks of each of the three treatment options outweigh the benefits and there is no expectation that this will change over time, meaning that there is no benefit from ‘watch and wait/higher threshold’ (see next page).

As aneurysms grow in size, so does the risk of rupture, most commonly occuring at 8cm.

An example of when you and your specialist might agree to ‘doing nothing’ is the better choice is when the risk of death after surgery is higher than the risk that the aneurysm will rupture. In other words, when surgery is in more dangerous than leaving the aneurysm untreated! You may also not benefit from aneurysm surgery if you have other significant health problems.

This decision is best discussed with your GP and family so that a plan can be put in place for in case your aneurysm does rupture.

‘Watch and wait’ or ‘higher threshold’

For most people, when a TAA becomes bigger than 6.0cm in diameter, they should start exploring the benefits and risks of having a planned aortic repair with their vascular surgeon. However, sometimes the patient and specialist agree not to repair the TAA but to ‘watch and wait’ to re-assess the benefits and risks when the TAA gets bigger.

It may also be more appropriate to wait until the TAA becomes a ‘higher threshold’ than 6.0cm for other patients due to fitness concerns or the shape of the aneurysm.

The decision to ‘watch and wait’ is best discussed with your GP and family so that a plan can be put in place for in case your aneurysm does rupture.

How do I decide which option is best for me?

Consider the benefits and risks of each option

Open surgery


  • Lower risk of further procedures
  • Preferred in Marfan’s syndrome


  • Higher risk of early death and complications
  • Longer hospital stay
  • Slower recovery
  • Risk of wound problems



  • Lower risk of death and complications
  • Shorter hosptal stay
  • Shorter recovery time


  • 1/5 risk of further procedure to keep TAA fixed
  • TAA could still rupture (less than 1% chance per year)
  • Risk of groin problems

Complex EVAR


  • Intermediate risk of death and complications
  • Intermediate hospital stay
  • Faster recovery


  • Delay for manufacture
  • 1/4 risk of further procedure to keep TAA fixed
  • TAA could still rupture (less than 1% chance per year)
  • Risk of groin problems

Watch and wait


  • Defers the risks of getting complications from surgery


  • 6.0cm TAA has a 5% chance of rupture per year
  • The risk increases as the aneurysm grows

Do nothing


  • No risk of getting complications from surgery


  • 6.0cm TAA has a 5% chance of rupture per year
  • The risk increases as the aneurysm grows

There are inevitably pros and cons to each choice. It is a good idea to think about what is most important to YOU. Your vascular specialist and the wider team may also have a strong recommendation. However, we always want to come to a shared decision over the best treatment choice for YOU.

Ask us questions

We want you to be an active participant in your healthcare. Tell us what is important to you and please ask us questions.

Considering the following three questions may be useful.You can also contact us by phone (details on next page).

  1. What are my treatment options, including 'do nothing'?
  2. What are the possible benefits and risks of each option?
  3. What help do I need to make my decision?

Read more

British Heart Foundation

NHS Choices

Healthy living

Adopting a healthier lifestyle and diet means that if have AAA surgery you will be in in the best possible health, both for the surgery itself and for recovery after.

If you or the individual you are caring for need support reading this leaflet please ask a member of staff for advice.

How to contact us:

Brunel building
Southmead Hospital
BS10 5NB

Vascular clinical nurse specialists: 0117 414 5302/3/4

AAA screening programme: 0117 414 8610

Patient pathway coordinators: 0117 414 0798

© North Bristol NHS Trust. This edition published August 2020. Review due August 2022. NBT003282

Treatment of thoracic aortic aneurysm (TAA)