Patient information on Endovascular repair of abdominal aortic aneurysm (EVAR) - ‘key hole’ repair of a ballooned artery in your abdomen

Who is this leaflet for and what is its aim?

This leaflet is for patients who have been diagnosed with abdominal aortic aneurysm (AAA) and have been recommended to have Endovascular repair of abdominal aortic aneurysm of the AAA.

This leaflet aims to explain the procedure and its risks.

Background information

An abdominal aortic aneurysm (AAA) is an abnormal dilatation (ballooning) of the aorta, caused by a weakness in the wall of the artery. The aorta is the main artery in the body and carries blood away from the heart. The other arteries in the body are supplied by the aorta. For example those that supply blood to the head, limbs and body organs.

Generally an artery is called aneurysmal when it increases to twice its normal size. Any artery in the body can develop an aneurysm but for some reason some arteries are more commonly affected than others. In particular the aorta, which is the main artery in the abdomen, is commonly affected as are the iliac arteries (in the pelvis), and the femoral arteries (in the thigh), and the popliteal arteries (behind the knee). The main risks of aneurysms are either that they burst (leading to life-threatening bleeding) or they block, therefore, cutting off the blood supply to the areas supported by them.

Aneurysms are more common in people aged over 60 years. They are also more common in people who have high blood pressure and/or those who smoke. Aneurysms can also run in families, particularly between brothers, because, in general, men are more commonly affected than women.

Diagnosis of AAA

The majority of AAAs cause no symptoms and are discovered by chance. A routine examination by a doctor or a scan performed for some other reason may pick up the presence of an aneurysm. Alternatively, some patients notice an abnormal pulsation in their abdomen (tummy). National screening for aneurysms in men at the age of 65 has now been established. For more information see the GOV.uk NHS abdominal aortic aneurysm (AAA) programme page (opens in a new tab).

Investigation of AAA

The majority of AAA can be diagnosed with a simple ultrasound scan, which also provides an accurate measurement of its size. The risk of rupture (bursting) of AAA is related to its size: AAA bigger than 5.5 cms (5.0cms in women) in diameter are at risk of rupture and require surgical repair to avoid this. Smaller aneurysms are monitored with ultrasound scans on a regular basis, and surgery is only considered if they increase in size, or start to cause pain or other symptoms.

When an aneurysm requires surgical repair, other investigations are arranged including a CT body scan. This provides accurate anatomical information regarding the aneurysm so the operation can be planned in more detail. The CT is particularly important when considering and planning EVAR (insertion of a stent graft into the aneurysm). Other investigations to measure the function of the heart, lungs and kidneys might also be arranged, because this surgery tends to put an extra strain on these organs.

The procedure

At the start of the surgery, we make two small wounds in the groin (these may in some circumstances be very small and almost be invisible to the naked eye). The aortic aneurysm will be fixed by passing the endovascular graft (a polyester or Gore-tex graft supported by metal struts) through the artery in your groin under x-ray control.

The wounds will be closed with glue or dissolvable sutures.

During surgery, you may lose blood. If you lose a considerable amount of blood your doctor may want to replace the loss with a blood transfusion as significant blood loss can cause you harm. The blood transfusion can involve giving you other blood components such as plasma and platelets which are necessary for blood clotting. Your doctor will only give you a transfusion of blood or blood components during surgery, or recommend for you to have a transfusion after surgery, if you need it.

Compared to other everyday risks the likelihood of getting a serious side effect from a transfusion of blood or blood component is very low. Your doctor can explain to you the benefits and risks from a blood transfusion. Your doctor can also give you information about whether there are suitable alternatives to blood transfusion for your treatment. There is a patient information leaflet for blood transfusion available for you to read.

After the procedure

Once your surgery is completed you will usually be transferred to the recovery ward where you will be looked after by specially trained nurses, under the direction of your anaesthetist.

The nurses will monitor you closely until the effects of any general anaesthetic have adequately worn off and you are conscious. They will monitor your heart rate, blood pressure and oxygen levels too.

You may be given oxygen via a facemask, fluids via your drip and appropriate pain relief until you are comfortable enough to return to your ward.

Some patients recover from aneurysm surgery in the theatre recovery area for the first night. However, you may go back to the ward on the day of surgery if there are no problems in recovery.

Sometimes, people feel sick after an operation, especially after a general anaesthetic, and might vomit. If you feel sick, please tell a nurse and you will be offered medicine to make you more comfortable.

At this time, you might find there is a urinary catheter inserted into your bladder, which allows your urine to drain into a bag. This is a temporary measure to prevent urine becoming retained which can cause your blood pressure to become unstable.

After certain major operations you may be transferred to the intensive care unit (ICU/ITU), high dependency unit (HDU), intermediate dependency area (IDA) or fast track/overnight intensive recovery (OIR). These are areas where you will be monitored much more closely because of the nature of your operation or because of certain pre-existing health problems that you may have. If your surgeon or anaesthetist believes you should go to one of these areas after your operation, they will tell you and explain to you what you should expect.

If there is not a bed in the necessary unit on the day of your operation, your operation may be postponed as it is important that you have the correct level of care after major surgery.

Intended benefits

To surgically repair your aneurysm, to prevent it either bursting or blocking.

Risks

As with any major operation there is a very small risk that you may have a medical complication such as a heart attack, pulmonary embolus, chest infection, kidney failure, DVT or stroke, but the doctors and nurses will try to prevent these complications and deal with them rapidly if they occur. There is also a small risk that the blood supply to the bowel may be compromised and this may require further abdominal surgery including a risk of a colostomy but this occurs in less that 1% of cases.

Sometimes after this surgery the blood supply to the legs can become compromised and further operations to restore the circulation are required and there is a small risk of amputation in less that 1% of cases.

Overall, the incidence of major complications (including death) is in the region of 1 in every 70 patients but the risks may be increased in those patients who have pre-existing disease. The risk of death is three times lower than for open aneurysm repair.

Other complications include surface nerve injury with numbness and discomfort after the operation in the legs. Also graft infection and wound infection. If the graft becomes infected this may require lifelong antibiotics or further surgery to remove the stent graft.

There is an extremely small chance that it may not be possible to manoeuvre the endovascular graft into the aorta and the surgeon may have to revert to open aneurysm repair (less than 1 in 100 risk). Overall there is a risk to your life in the early post-operative course of between 1-2% of cases in most patients.

Endovascular AAA repair (EVAR) involves insertion of a stent within the aorta and as such we will keep a close eye on your endovascular graft for life after surgery with regular scans. Occasionally blood may leak around the endovascular graft ‘endoleak’ and up to one in 10 patients may require a further procedure at a later date. However if required this is often a small procedure performed under a local anaesthetic. There is a very small chance that the endovascular graft may need to be removed at a later date and the aneurysm repaired by a conventional technique. Our experience to date shows this is uncommon.

Alternatives

Monitoring only

If you have other health problems (heart disease, poor breathing for example) this may increase the risk of the operation. Occasionally in that situation we elect to continue monitoring the AAA until a larger size. The aim is to balance the risk of the procedure against the risk of rupture from the aneurysm. Rarely in patients with many other conditions the decision is made with you to not carry out a repair. This will be fully discussed with you.

Open aneurysm repair

This is an alternative technique. This is a larger operation where the aneurysm is repaired with a graft sewn into the aorta through a larger incision in the abdomen.

Medication

Bring all of your medicines (including inhalers, injections, creams, eye drops or patches) and a current repeat prescription from your GP.

Please tell the ward staff about all of the medicines you use. During your stay If you wish to take your medication yourself (self-medicate) please speak with your nurse. Pharmacists visit the wards regularly and can help with any medicine queries.

MyChart

We would encourage you to sign up for MyChart. This is the electronic patient portal at Cambridge University Hospitals that enables patients to securely access parts of their health record held within the hospital’s electronic patient record system (Epic). It is available via your home computer or mobile device

More information is available on our website: MyChart

Contacts

We may give you additional patient information before or after the procedure, for example, leaflets that explain what to do after the procedure and what problems to look out for. If you have any questions or anxieties, please feel free to ask a member of staff or our vascular specialist nurses on 01223 348526 or email the vascular nurses.

Further information is available from:

• The Vascular Society (opens in a new tab)
• Circulation Foundation (opens in a new tab)