Abdominal Aortic Aneurysm - Endovascular Repair
This leaflet gives only general information for patients. Your medical practitioner will be able to answer any specific questions you may have on your condition.
1. What is an Aneurysm?
An aneurysm is a stretching of a weakened artery, which balloons out rather like a worn motor car tyre. The wall of the artery becomes thinner by the loss of its elastic tissue and the artery then inflates making it likely to rupture (burst). The most common artery to be affected is the aorta, which is the main artery in the abdomen.
Many thousands of people each year suffer from rupture of an abdominal aortic aneurysm. Most of these patients are men over the age of 60 years. Smoking and high blood pressure are known to increase the risk.
2. How is an Abdominal Aortic Aneurysm detected?
Ultrasound scan of AAA
Some patients have the aneurysm diagnosed coincidentally when they are examined for another problem, or if they have a scan for a different reason (kidney trouble, or gallstones, for example). Occasionally, the patient may become aware of a feeling of pulsation in the abdomen. As the aneurysm stretches, it can also cause pain in the back or abdomen. If an aneurysm is suspected, your physician will refer you to a vascular specialist for advice; either your physician or vascular specialist will refer you for an ultrasound scan. Ultrasound scanning of the abdomen is a painless outpatient test that only takes a few minutes to do. It is used to decide whether an aneurysm is present. A more detailed x-ray of your abdomen, called a Computed Tomography (CT) scan, may then be carried out to determine the exact size of the aneurysm.
3. Who is at risk?
It is known that men over the age of 60, younger men with a brother or father who has had an aneurysm, or men with other arterial disease (angina, hardening of the arteries or high blood pressure) are at risk. In some areas, people at increased risk of having an abdominal aortic aneurysm are being offered screening by ultrasound scan.
4. Do I need surgery?
Not all aneurysms need an operation. The risk of rupture and therefore the need for repair depends on the size of the aneurysm. If the aneurysm is large (more than 5 cms in diameter), it is probably safer to have an operation to repair it than to leave it alone. This protects the aorta from rupture. Smaller aneurysms are usually observed by repeat scanning at 6 to 12 monthly intervals, in case they enlarge and become dangerous. Average enlargement is about 0.5 cm per year, so surgery may be required at a later stage. Your vascular specialist will give you a clear explanation of the options in your case.
5. What does surgery involve?
Surgery involves the insertion of a new lining into the aorta (like the inner tube of a tyre) made of a very strong material called polyester. This new lining can be inserted in the aorta in two ways; open surgical repair or endovascular repair. Open surgical repair is a method of treating an abdominal aortic aneurysm. This involves making a large incision in the abdomen in order that the physician can handle the aorta and repair the aneurysm using a polyester tube. Endovascular repair is performed through two small incisions, one in the left and one in the right side of the groin. A polyester tube, called a “stent graft”, is passed through these small incisions and fed through the arteries until it is in the aorta inside the aneurysm. Once inside the aorta, the stent graft expands to allow blood to flow through the stent graft and to stop blood from entering the aneurysm.
6. Is surgery successful?
If aneurysms are repaired before they rupture, there is a high overall chance of successful repair and a return to normal life expectancy. However, you should discuss the risks of surgery in your particular case with your physician.
7. How can I help myself?
There is nothing you can do about the aneurysm. However, improving your general health under medical supervision by taking regular exercise, losing weight and stopping smoking is helpful.
8. Why do I need the operation?
Because the main artery (aorta) in your abdomen has stretched and weakened (aneurysm). This operation is to repair the stretched section so that it will not rupture (burst).
9. Before your operation
You will usually be admitted to hospital one day before your operation and you may be asked to attend a pre-admission clinic about a week earlier in order to allow time for any tests required. This is to ensure that you are fit for your operation. These tests may include blood tests, scans of the abdomen and x-rays of the arteries (arteriogram) if these have not already been done.
10. 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 note down your personal details in your nursing records. Prior to surgery, you will undergo a number of investigations, if these have not been performed previously, including a heart tracing, a chest x-ray and blood tests. You will be visited by the physician who will be performing your operation and also the specialist who will give you the anaesthetic. If you have any questions regarding the operation please ask the physician.
11. The operation
You will initially be taken to a reception area in the theatre suite, then to the anaesthetic room where you will be given your anaesthetic, and then into the theatre. You may have a general anaesthetic, which will send you to sleep, or you may have a local or spinal anaesthetic so that you remain awake during the operation but feel no pain. Tubes may also be inserted into your bladder to drain your urine, into an artery in your arm for blood pressure measurements and also into a vein in your arm or neck for administration of fluid during and following surgery. Once in the operating theatre, you will have a cut made in each groin area (see figure 3).
The aorta, and particularly the swollen area, will be replaced by an artificial tube made of polyester as shown in fig 4-6.
The physician will introduce the polyester graft (tube) into your aorta via the cuts in each groin. This is done by placing a guidewire (stainless steel wire) through each groin into the artery and up the inside of the artery into the aorta (see figure 4). The polyester graft is then delivered over the guidewires and opened out in the aorta (see figure 5). The construction of the polyester graft means it will adhere to the inside wall of the artery. Once the graft is in place and the aneurysm is repaired the physician will stitch the cuts in your groin (see Figure 6). The operation is viewed using x-rays so that the physician can see the polyester graft inside your aorta.
12. After the operation
You may be taken to the high dependency unit or back to the ward following your operation, where your progress will be monitored closely. You will initially be given some oxygen through a face mask or a small tube which is placed at the entrance of your nose. A blood transfusion may also be required. You will be able to start eating and drinking as soon as you feel well enough. The nurses and doctors will try and keep you free of pain by giving painkillers by injection, tablet or via a small tube in your back (epidural). In the next 1-2 days as you improve, the various tubes will be removed.
13. Going home
If dissolvable stitches have been used, these do not need to be removed. If your stitches or clips are the type that need to be removed, and this is not done whilst you are still in hospital, the practice or district nurse will remove them and check your wound. You may feel tired for some time after the operation but this should gradually improve as time goes by. Regular exercise, such as short walks 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 at least 4 weeks after surgery. If in doubt check with your physician.
Bathing: Once your wounds are dry, you may bathe or shower as normal.
Work: You should be able to return to work within 1-3 months following your operation. If in doubt please ask your physician.
Lifting: You should avoid heavy lifting or straining for 6 weeks after the operation.
As with any surgery, there are potential complications during and after the procedure. The physicians and nurses will try to prevent any complications during surgery and will deal with them rapidly if they occur. Slight discomfort and twinges of pain in your groin wounds are normal following surgery, but wounds sometimes become infected and these can usually be successfully treated with antibiotics. Also the wounds in your groin can fill with a fluid called lymph that may leak between the stitches but this usually settles down with time.
In order to detect complications after surgery, it is important that you attend regular follow-up appointments arranged by your physician. Normally, follow-up appointments are scheduled regularly in the first year after your surgery, then annually thereafter. These follow-up appointments may include ultrasound, x-ray and CT scans to check that the stent graft is working correctly, together with a physical examination.
15. What can I do to help myself?
If you were previously a smoker, you must make a sincere and determined effort to stop completely. Continued smoking will cause further damage to your arteries and your stent graft is more likely to stop working. General health measures such as reducing weight, a low fat diet and regular exercise are also important.