What investigations will I need ?
To diagnose the aneurysm, an ultrasound scan is all that is necessary. This allows a measurement to be made of the aneurysm. An ultrasound machine is used for screening for aortic aneurysms in the population. The following shows a typical image obtained:
You will see a dark inner 'circle' outlined by the yellow line. This represents the 'lumen' - the hole in the centre of the artery along which blood flows. The outer red circle is the outer wall of the aortic aneurysm and represents its true diameter - this is the one we measure as the size of the aneurysm. The area between the 2 lines is 'thrombus' and a specimen is shown in the picture on the right. It is a collection of atheroma and blood cells including platelets (sticky blood cells), red and white cells.
The frequency of scans depends on the size of the aneurysm:
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for aneurysms between 3 - 4 cm, a yearly scan is needed |
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for aneurysms between 4 - 5 cm, a 6 monthly scan is needed |
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for aneurysms more than 5 cm, a 3 monthly scan is needed |
Once the aneurysm is more than 5.5 cm an operation will be considered and a CT scan requested to outline the anatomy in greater detail (especially the relationship to the renal arteries). To obtain the CT scan you will be asked to drink a fluid which outlines the intestine and a dye will be injected into a vein to outline the blood vessels:
The white area in the middle is the lumen of the aneurysm - it shows up because of the injected dye. The light grey area around it is the aortic aneurysm wall. You can see the backbone and part of the pelvis at the bottom of the picture (bone appears white). With newer CT scanners 3D pictures of the aneurysm can be generated - these give far more detailed picture of the aneurysm anatomy than before.
You will also need investigations to make sure you are fit enough for surgery. These will include:
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blood tests to make sure your kidneys are working properly |
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a heart tracing (ECG) |
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a chest x-ray |
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more specialised heart tests may be needed. These include an exercise tolerance test (an ECG whilst exercising), an echocardiogram (an ultrasound scan of the heart) or an angiogram of the coronary arteries (the ones that take blood to the heart muscle). |
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if you have lung disease, tests of your breathing capacity (lung function tests) may be needed |
If there is a history of heart disease you may have to see a cardiologist (heart specialist) before an operation is undertaken.