A painful swollen leg is the commonest presentation of a deep vein thrombosis (DVT). However many other things cause painful swollen legs and also some DVT present in other ways. Therefore, before we think about treatment of DVT, we have to make sure that we are treating a deep vein thrombosis and nothing else instead.

Tests

There are some blood tests that are used in accident and emergency departments for screening for deep vein thrombosis (DVT) but, as the screening test, these are not highly accurate. Also some people use heat imaging cameras or techniques, once again these are not highly accurate.

The best test currently available for diagnosing deep vein thrombosis (DVT) is a colour flow duplex ultrasound performed by an experienced expert. There are several different sorts of colour flow duplex ultrasound and to be able to diagnose small deep vein thromboses in the calf, a very high resolution machine is required operated by someone who is expert in scanning veins.

Treatment

The usual treatment for deep vein thrombosis is to thin the blood using anticoagulants. This usually entails injections of heparin which act immediately, whilst oral warfarin is started and stabilised. Warfarin combats the vitamin K in the body which is used for blood clotting. It is usually started by giving a loading dose for three days and then using blood tests to stabilise the right dose over the next few days to weeks.

The body is able to break down most clots by itself and so the heparin followed by the warfarin is merely there to stop any more clot forming whilst the body breaks down the deep vein thrombosis (DVT) that is already there.

Traditionally doctors have kept the warfarin going for three to six months. However, we now tend to rescan the leg to make sure the blood is flowing while before deciding whether the warfarin can be stopped or not.

The very rarely, if there is a massive deep vein thrombosis which is a risk of either blocking the veins completely or breaking off and going up through the system to the lungs (a pulmonary embolism), then either a clot busting injection called thrombolysis can be used to break down the clot, or a filter can be put into the veins to catch the clot if it breaks off.