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Date issued: December 2023

Review date: December 2025

Ref: A-606/JW/Vascular/Abdominal Aortic Aneurysm General Information and Treatment

PDF:  Abdominal Aortic Aneurysm General Information and Treatment.pdf[pdf] 325KB

What is an Aneurysm?

Aneurysms result from stretching of a weakened artery, which balloons out rather like a worn motorcar tyre. When this happens, there is a risk that the artery may burst. The most common artery to be affected is the aorta, which is the main artery in the tummy (abdomen). The normal aorta is about 16-22mm (just under 1”) in diameter. In England and Wales, between 6,000 and 10,000 people each year suffer from rupture (bursting) of an abdominal aortic aneurysm. Most of these patients are men over the age of 65 years. 1 in 10 men over 65 may have some enlargement of the abdominal aorta. About 1 in 100 will have a large aneurysm requiring surgery.

Why have I got an abdominal aortic aneurysm (AAA)?

We don’t know why aortic aneurysms develop but something weakens the artery wall. Aneurysms are more common as you get older and are more common in men. Other risk factors also include smoking, high blood pressure and a family history of aortic aneurysm.

How do you detect an aortic aneurysm?

An aneurysm is easy to diagnose with an ultrasound scan of the abdomen and it is quite common for aneurysms to be found incidentally in patients having a scan for another reason. If we do find an aneurysm and it is near a size where we want to operate, then we will arrange for you to have a CT scan (body scan). This gives us more information about the aneurysm to be able to plan the appropriate method of treatment. A National Screening Programme has recently been introduced in men over the age of 65 years who will be offered an ultrasound scan to detect those with aneurysms.

When do we decide to operate on an aneurysm?

We do not operate on all aortic aneurysms for several reasons. There will always be a discussion between you and the Surgeon about the risks and benefits of an operation depending on how fit and well you are and many factors are taken into account. If the aneurysm is smaller than 5-5.5cm we tend to arrange ultrasound scans at regular intervals to monitor its size as the risk of it bursting is small, probably less than 1 in 50 each year. If the aneurysm is around 5-5.5cm we tend to offer intervention as these have a higher risk of bursting if left untreated (about 1 in10 each year). The risk of the aneurysm bursting increases as the aneurysm gets bigger so that an aneurysm larger than 7cm probably has a risk of bursting of about 1 in 3 each year. Because most aneurysms grow slowly over time, there are many patients who are followed with regular ultrasound scans and eventually need to have an intervention, but there doesn`t seem to be any overall benefit in treating aneurysms when they are small. However, we will operate on small aneurysms if they are causing pain or if we have other concerns about the nature of the aneurysm.

What treatments do we have for aortic aneurysms?

For many years, the standard treatment of an aortic aneurysm was an open operation (open repair or graft) but since 1990 we have seen the introduction of Endovascular Aneurysm Repair (EVAR or stenting).

Open operation: this is still a very good treatment and in most cases can be regarded as a cure. This involves a vertical or horizontal incision in the abdomen and occasionally also in the groins. The aorta (which runs at the back of the abdomen) is clamped so that it can be opened up and a tube of fabric (usually Dacron) stitched inside it. Sometimes a tube with two ends like a pair of trousers is required to take blood to both legs. The tube allows blood flow to continue to the organs and the legs but stops blood flowing into the aneurysm so that it stops getting bigger and eventually shrinks in size. The operation requires a general anaesthetic (to send the patient to sleep) and often needs a 1-2 week stay in hospital.

Endovascular aneurysm repair: in this operation, a fabric tube with a metal support (stent) is inserted into the aneurysm in a collapsed state inside a delivery tube, through two small incisions in the groins. The tube is then opened up after it has been placed inside the aneurysm. The tube stays in place by small hooks and fixes to the aneurysm wall as it expands. The operation which involves x-rays can be done in theatres or in the x-ray department. It is often done under general anaesthetic but can be done with other forms of anaesthetic (epidural / spinal) and even under local anaesthetic. The operation usually requires a 2-4 day stay in hospital.

What tests will you have before your operation?

Before aortic surgery, there are a number of tests that need to be done and these are of two types.

Tests of fitness and suitability are normally done before a decision to operate is made. They normally include blood tests, ECG (electrical tracing of the heart), chest x-ray if needed, an ultrasound scan of the heart (ECHO) and often a test that measures your breathing on exercise (cardio-pulmonary exercise test or CPX).

Immediate pre-operative tests include blood tests,another ECG and completing the paperwork. These tests are usually completed at a pre-admission visit to the hospital a few days before your operation. They are sometimes done when you are admitted for the operation.

How do I choose which operation to have?

The Surgeon will discuss the options at a multidisciplinary meeting and then see you in outpatient clinic to discuss the optimal treatment. Not all aneurysms are suitable for EVAR and not all patients are suitable for open surgery.

Open abdominal aortic aneurysm (AAA) repair

Open aneurysm repair has been around for many decades and, in most cases, can be regarded as a cure. The operation involves a vertical or horizontal incision (cut) in the abdomen (tummy) and occasionally also in the groins. The aorta which runs at the back of the abdomen is clamped so that it can be opened up and a tube of fabric (usually Dacron) stitched inside it. Sometimes a tube with two ends like a pair of trousers is required to take blood to both legs. The tube allows blood flow to continue to the organs and the legs but stops blood flowing into the aneurysm so that it stops getting bigger and eventually shrinks in size. The operation requires a general anaesthetic (asleep) and often needs a 1-2 week stay in hospital.

What are the risks of the operation?

There are risks with any operation. These will be discussed with you in the clinic and again in hospital when you are consented for your operation. Open aortic surgery is major surgery and carries a 1 in 33 risk of death. These risks tend to be lower if you are young, fit and well and higher if you are older or have other medical problems. The risk of another complication is also approximately 1 in 33 and could include:

• Wound infections are uncommon and we take great care to keep the whole operation sterile. Most wound infections settle with appropriate dressings or antibiotics.

• Graft infection is very rare (less than 1 in 100). At the time of surgery we give you antibiotics to prevent infection and we also soak the graft in antibiotic. If the graft does get infected, it often only becomes apparent several years later and is a very serious condition usually requiring further major surgery.

• Heart attacks and heart failure are possible complications during and after any aortic surgery, especially if you have some degree of heart disease before the operation.

• Chest infections are not uncommon but are usually treatable with antibiotics but occasionally require a period of assisted ventilation in intensive care. 

• Kidney failure can be a problem. It is more common if there is kidney disease before the operation and if we need to clamp the aorta above the kidney arteries during the operation. Usually, it recovers but rarely it can persist requiring temporary or permanent dialysis.

• Stroke is rare but we may perform a scan of the neck arteries before your operation to help us assess this risk. However, the value of doing this is as yet unproven and not all surgeons do this.

• Loss of blood supply to part of the bowel is very rare but, if it does occur, it usually presents a few days or a week after the initial operation with lower abdominal pain and signs of infection. If suspected, further tests may be done and it may necessitate a further look inside the abdomen. If a part of the bowel has lost its blood supply it usually means removal of this part of the bowel with the formation of a temporary (occasionally permanent) colostomy (a bag).

• Deep vein thrombosis (DVT). We try to prevent this by giving a daily injection under the skin before the operation and every day after until you are mobile again and by using stockings. Occasionally a clot can pass to the lung causing a pulmonary embolus (PE) which can be a serious condition but is usually treatable with anticoagulant medications.

• Loss of blood supply to a leg. The aorta carries the blood supply to both legs and rarely clots or debris from inside the aneurysm can pass down into the leg(s). If this happens we will do everything we can to remove the clot but on very rare occasions the leg may not survive requiring amputation.

• Impotence. The nerves that control the sexual organs run in front of the aorta. Problems with erection and ejaculation are not uncommon after the open operation (about 1 in 4).

What is Endovascular Aneurysm Repair (EVAR)?

For many years, the standard treatment of an aortic aneurysm was an open operation (open repair or graft) but since 1990 we have seen the introduction of endovascular aneurysm repair.

In EVAR a fabric tube with a metal support (stent) is inserted into the aneurysm in a collapsed state inside a delivery tube, through two small incisions in the groins. The tube is then opened up after it has been placed inside the aneurysm. The tube stays in place by small hooks and fixes to the aneurysm wall as it expands. The operation which involves x-rays can be done in theatres or in the x-ray department and is usually done in conjunction with one of the Radiologists. It is often done under general anaesthetic but can be done with other forms of anaesthetic (epidural / spinal) and even under local anaesthetic. The operation usually requires a 2-4 day stay in hospital.

What are the benefits of EVAR?

EVAR involves much smaller incisions than open repair so the risk of wound problems is low. Also, the incisions are less painful so the recovery to normal eating, mobility and return to home is generally much quicker (a shorter stay in hospital). There are smaller risks of heart attack and chest infections because the procedure is minimally invasive.

What are the risks of the operation?

There are risks with any operation. These will be discussed with you in the clinic and again in hospital when you are consented for your operation. Aortic surgery is major surgery even by the EVAR method but some of the risks with EVAR are lower than with open surgery. EVAR carries a 1 in 100 risk of death. These risks tend to be lower if you are young, fit and well and higher if you are older or have other medical problems. The risks are similar to those of open surgery.

Complications specific to endovascular repair include endoleaks and slippage or breaking of the stent graft. The EVAR relies on a good seal between the stent and the wall of the aorta, if the seal is not good it is possible for blood to track down the side of the stent or for the aneurysm to continue to fill with blood from vessels at the back (endoleak). Some endoleaks are important and need to be treated and some are less important and can just be observed. It is very rare for an endoleak to require open surgery. Slippage or breaking of the stent is also very rare with modern devices and can usually be treated with a further x-ray procedure. In the early years of these stents, there were some problems with stent design making “re-intervention rates” (the need to perform a further procedure to put a problem right) quite common (around 1 in 5). However, with modern stent design this problem is much less and we now only see a problem with about 1 in 15 stents.

With EVAR, you can often drink straight away and will be back to eating very soon after. You will become gradually more mobile until you are fit enough to go home. You may be visited by the physiotherapists after your operation who will help you with your breathing to prevent you developing a chest infection and with your mobilisation to get you walking again.

Coming into hospital

Please bring with you all the medications that you are currently taking. You will be admitted to your bed by one of the nurses who will also complete your nursing record. You will be visited by the Surgeon who will be performing your operation and also by the doctor who will give you the anaesthetic. Your operation, in exceptional circumstances, may be performed by a Vascular Consultant who did not assess you in clinic. Physiotherapists and Intensive Care staff may also visit, to give you information about your post-operative care. If you have any questions regarding the operation, please do not hesitate to ask.

The anaesthetic

The first part of the operation involves giving you an anaesthetic. The open operation can only be done with you asleep. The endovascular operation can be done asleep or awake. If you go to sleep, a needle is placed in the back of your hand. The anaesthetic is injected through the needle and you will be asleep within a few seconds. You may well have a tube put into a vein in the neck to give you intravenous fluids and monitor how well hydrated you are (a central line). A tube may be inserted into an artery in the wrist to monitor your blood pressure (an arterial line). If you are to be awake, you will have a small tube placed in your back. This may be a spinal or an epidural anaesthetic.

• Aspinal anaesthetic stops you from feeling anything from the waist downwards on the operation side. The leg is paralysed and this lasts for about 3-4 hours.

• An epidural stops you from feeling anything from the waist downwards and affects both legs but there is no paralysis. The epidural is like a drip and can stay in for several days to provide post-operative pain relief.

• A tube (catheter) may be inserted into your bladder to drain your urine if you have a general anaesthetic. The catheter is essential if you have either the spinal or epidural.

After the operation

The open operation is a major operation and inevitably the recovery is longer. You will usually be taken to the high dependency unit (HDU) or intensive care unit (ICU) for close monitoring, sometimes for several days. The recovery after an endovascular operation is generally much quicker and may only involve a few hours in HDU.

After your operation, you will be given fluids by a drip in one of your veins until you are well enough to sit up and take fluids and food by mouth. The nurses and doctors will try and keep you free of pain by giving pain killers by injection, via the epidural tube in your back, or by a machine that you are able to control yourself by pressing a button (Patient Controlled Analgesia PCA). Within a day or so, the drip, epidural and bladder catheter will be removed. If you have had an open operation it takes a few days for your bowel to work properly, and you will only be allowed small amounts of fluid for a few days before getting back to normal diet.

Going home

If your stitches or clips are of the type that needs removing, this is usually done whilst you are still in hospital. If not, we will arrange for your GP practice or district nurse to remove them and check your wound. You may feel tired for some weeks or months after the operation but this should gradually improve. Regular exercise such as a short walk combined with rest is recommended for the first few weeks following surgery followed by a gradual return to your normal activity.

• Driving: You will be safe to drive when you are able to perform an emergency stop. This will normally be 4-6 weeks after surgery, but if in doubt check with your own doctor.

• Bathing: Once your wound is dry you may bathe or shower as normal.

• Work: You should be able to return to work within 6-12 weeks of surgery. We will provide you with a sick note but if you need longer off work, please see your GP.

• Medicines: You will usually be sent home on a small dose of aspirin if you were not already taking it. This is to make the blood less sticky. If you are unable to tolerate aspirin, an alternative drug may be prescribed.

• Sometimes you may experience numbness or tingling around the groin wounds or lower down the legs afterwards.  This is due to bruising or cutting of small nerves to the skin.  It can be permanent, but usually gets better within a few months.

• It is also common for your feet to swell due to improved blood supply, decreased mobility just after the operation and a fall in your body proteins which always occurs after an operation.  Elevation of the legs when sitting helps the fluid to disperse and a nutritious diet will build up your body proteins.

• As with any major operation, there is a very small risk of you having a medical complication, but the doctors and nurses will try to prevent these complications and to deal with them rapidly if they occur.

What can I do to help myself?

If you were previously a smoker you must make a sincere and determined effort to stop smoking completely. Continued smoking increases your risk of wound problems, chest infections, DVT, stroke and heart attack. It also causes further damage to your arteries which can cause the graft to block off. Why not take this opportunity to consult your own doctor or the practice nursing staff to seek professional help in giving up the addiction?

Further help is available locally from the

Smoking Advice Service, Tel: 0300 123 1044, NHS Stop smoking

General health measures before the operation such as reducing weight, a low fat diet and regular exercise are also important and will speed up your recovery.

What follow up will I have?

We will usually see you in the clinic at about 6-8 weeks after your procedure. If you have had an open operation and you have no problems, you will probably be discharged at that point. If you have had the EVAR, we currently perform regular monitoring of the stent graft for life.

Contact details

Vascular Surgical Unit

Surgical Directorate

Plymouth Hospitals NHS Trust

Derriford Hospital

PL6 8DH

Tel 01752 202082

Consultant Vascular Surgeon and Lead Clinician

Mr Devender Mittapalli

Secretary: 01752 431822

Consultant Vascular and Transplant Surgeon

Mr Jamie Barwell

Secretary: 01752 431822

Consultant Vascular Surgeon

Surgeon Commander Cris Parry RN

Secretary: 01752 431822

Consultant Vascular Surgeon

Miss Catherine Western

Secretary: 01752 431805

Consultant Vascular Surgeon

Lt Col Robert Faulconer

Secretary: 01752 431805

Consultant Vascular Surgeon

Mr Hashem Barakat

Secretary: 01752 431822

Vascular Scientists

• Mrs J George
• Mr A Ellison
• Mr R Craven

01752 439228

Vascular Nurse Specialist

Mr Alan Elstone

01752 431805

Matron

Judy Frame

01752 431847