Investigation of varicose veins
Most patients with varicose veins do not need specialised tests - examination by a specialist and listening with a hand-held doppler is all that is needed.
Sometimes a more detailed scan of the veins is necessary. This is done with a duplex machine - gives pictures of the anatomy and indicates the direction of blood flow. This test is painless and involves the application of a jelly to the skin and a probe is used to obtain the pictures (it is similar to the scan pregnant women have). We use it :
 | if there is uncertainty about the exact sites of problem - especially with the junction behind the knee. |
| in patients with recurrent varicose veins where there may be more than one site of leaking junctions. |
| in patients with ulcers due to venous problems to check the state of the deep veins and to see if surgery would be useful. |
The video below shows the sapheno-femoral junction. The femoral vein is along the bottom and the saphenous vein comes of it. The head-end of the patient is to the left. If the calf is squeezed, blood flows along the veins (blue colour - blood flowing away from the probe). When the pressure is released blood should not flow back - but in this case it can be seen to flow down the long saphenous vein (red colour - blood flowing towards the probe). The close-up of the junction shows the valve that normally guards this junction.
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We can assess if the veins are working properly despite the presence of varicose veins by using 'photoplethysmography'. This involves sticking a small probe to the skin near the ankle and getting you to bend your ankle up and down a few times in time to a beat. The computer then tells us if the blood empties out of your leg properly and how quickly it flows back in again. The veins are not working properly if the blood does not empty from the leg adequately and returns too quickly. The site of the problem can be determined by repeating the test with tourniquets at different levels on your leg.