Abdominal Aortic Aneurysm
1. 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 in diameter.
- In India , a large number of people each year suffer from rupture (bursting) of an abdominal aortic aneurysm. This is one of the commonest causes of sudden death; but in India , it remains under diagnosed. Most of these patients are men over the age of 60 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.
2. How is an Abdominal Aortic Aneurysm (AAA) detected?
- An aneurysm may be detected when your Doctor examines your abdomen, but many cannot be felt. Occasionally, a patient may become aware of a feeling of pulsation in the abdomen. On rare occasions, a lump can be visible.
- An ultrasound examination of the abdomen is a very good way of finding an aneurysm. This is a painless procedure involving a lubricated probe pressing gently on the abdominal skin (over the aneurysm). The scan will tell you if there is an aneurysm present and exactly how large it is.
- Some patients have the aneurysm diagnosed by chance when they are examined for another problem, or if they have a scan for a different reason (prostate and kidney trouble, or gallstones, for example).
- As the aneurysm stretches, it may cause tummy or back pain. Sometimes the aneurysm is first discovered when this pain is investigated.
- If an aneurysm is suspected, your GP will refer you to a Vascular Surgeon for advice. Either your GP or specialist will arrange an ultrasound scan.
3. Who is at risk?
- Aneurysms are much more common in males than females.
- It is known that men over the age of 60, and younger men with a brother or father who has had an aneurysm, are at risk.
- Men with other arterial diseases (angina, hardening of the arteries or high blood pressure) and smokers are also at risk.
4. Do I need surgery?
- Not all aneurysms need an operation. The risk of rupture and therefore the need for an operation depends on the size of the aneurysm (the risk of rupture increases as the aneurysm gets bigger).
- If the aneurysm is large (more than 55mm in diameter), it may be safer to have an operation to repair it than to leave it alone.
- Because the operation itself carries some risk, the exact size at which your surgeon will advise an operation will also depend on any other health problems that you may have. For instance, if you have heart, lung, or kidney problems an operation may be more risky for you than for some other patients.
- Once repaired, the risk of rupture disappears.
- Ideally, an operation is advised when the threat of the aneurysm bursting (which is usually fatal) is more than the risk of an operation.
- If your aneurysm is smaller than the size at which operation is needed, your surgeon will arrange further ultrasound scans (usually once a year) to monitor the rate of growth.
- Aortic aneurysms generally grow slowly. At diameters up to 50mm (about 2 inches), the rate of growth is between 1-4mm per year. When aneurysms are more than 50mm in diameter, the rate of growth increases to 4-6mm per year.
If an aortic aneurysm ruptures, the chances of survival are not good. Overall only 2 in 10 will survive. Half the patients with aortic rupture will die before they reach hospital.
- Your specialist Vascular Surgeon will give you a clear explanation of the options in your case.
5. What does surgery involve?
- Many aneurysms are treated by an operation on the tummy in which the aneurysm is replaced with an artificial artery made of a very strong plastic material called Dacron. This artificial artery should last for the rest of your life and it is very unlikely that it will need to be replaced.
- Some aneurysms may also be suitable for treatment by a new method in which the graft is threaded up into the aortic aneurysm through a small incision in each groin.
- If your aneurysm is suitable for this type of treatment (approximately 6 in 10 are), your surgeon may discuss this with you. The treatment is called Endovascular Stenting (see under EVAR).
6. Is surgery successful?
- If aneurysms are successfully repaired, there is a very high likelihood that you will return to a normal life. Full recovery times vary between 3 and 6 months, depending mostly on your age. Your surgeon will discuss any special risks of surgery in your particular case with you.
7. How can I help myself?
- As far as we are aware, there is nothing you can do which will make the aneurysm worse, but there is also nothing you can do to make it better.
- Improving your general health by taking regular exercise, rigorous control of blood pressure, losing weight and stopping smoking are helpful even if you do not need an operation at present.
It is advisable for all males above 60 years of age to have an ultrasound scan of the abdomen (and a chest x-ray for aneurysms in the chest) to screen for the presence of an aneurysm.