Upper Limb Deep Vein Thrombosis Duplex Ultrasound

Blood clots are often something that people think about when they do a long-haul flight. However, there are other common reasons people can develop blood clots.

• Injury – for example a knee injury may cause you to be unable to walk properly for a period of time. Immobility is a significant risk factor for deep vein thrombosis.
  
• Surgery – undergoing a surgery is similar to having an injury, you are often immobile for a period of time. Sometimes your surgeon will prescribe blood thinners whilst you are in the hospital to minimise the risk of developing a blood clot.
  
• Blood clotting disorders – some people can be genetically predisposed to developing clots in their blood, for example a genetic mutation called “factor V leiden” increases your risk of developing blood clots significantly.
  
• Other risk factors for blood clots can also include; cancer, obesity and oral contraception.

The medical term for a blood clot is a thrombus and if it forms in a major vein, the term is deep vein thrombosis. This means the blood in the deep veins in your arms has changed into a jelly like material which has then got stuck in the vein. A new deep vein thrombosis (called acute thrombosis) needs to be diagnosed and treated urgently.

There are two immediate problems if you get a deep vein thrombosis; the first is that they can be painful and can cause the limb to swell.

The second and the more urgent problem is the risk of the deep vein thrombosis breaking off and passing up through the veins back to your lungs. In some cases this can cause serious breathing problems. If you experience any symptoms like this then you should urgently attend the emergency department as this must be treated immediately.

The sonographer can use the ultrasound machine to image inside the veins of your arms to see if there is any new deep vein thrombosis or to see if you may have evidence of having had a deep vein thrombosis in the past (called chronic thrombosis). Using the transducer and gel they will press firmly along the entire length of your arm in order to make sure that the deep vein will compress. If it compresses then it means there isn’t any thrombus. If, however the vein won’t compress then that indicates there may be deep vein thrombosis present. The sonographer will make sure that they have recorded the location of any deep vein thrombosis so that it can be compared to the next scan often a week later.