What is it about ?
Venous thromboembolism (VTE) is caused by the presence of a clot (thrombus) in a vein, usually in a leg. When a clot in a deep vein (deep vein thrombosis) of the leg causes an obstruction, the blood has difficulty returning to the heart. A piece of the clot may also break off (embolus) and be carried with the blood to the heart. It then passes into the lungs. The clot can then block a blood vessel in the lungs. This is called a pulmonary embolism.
The risk factors for venous thromboembolism are, in particular
- have already had a VTE,
- advanced age,
- smoking,
- obesity,
- diabetes,
- certain liver diseases (fatty liver and cirrhosis),
- certain kidney diseases
- certain chronic intestinal diseases (systemic lupus erythematosus, etc.),
- obstacle to venous return,
- Cancer,
- hereditary factors (coagulation diseases, for example),
- be in bed with a serious illness such as a serious infection, heart failure or dehydration,
- prolonged immobilization (long flight in an airplane, plaster cast, paralysis, etc.),
- certain surgical operations (for example hip or knee surgery),
- pregnancy, childbirth, period after childbirth (postpartum),
- certain hormonal treatments (hormonal contraception, hormonal replacement therapy, etc.).
How to prevent it?
Types of anticoagulant drugs
The anticoagulant drugs are drugs that prevent the blood from clotting, forming clots. They are sometimes said to ‘thin’ the blood.
Some are administered once or twice a day as an injection under the skin (subcutaneous injection), these are low molecular weight heparins (LMWH). You can learn to give the injection yourself or have a nurse give it. In Belgium, low molecular weight heparins are
- Dalteparin under the brand Fragmin®
- Enoxaparin under the brand name Clexane®
- Nadroparin under the brands Fraxiparine® and Fradoxi®
- Tinzaparin under the brand Innohep®
Others are in the form of tablets, these are the oral anticoagulants. In this category, we find vitamin K antagonists and direct oral anticoagulants. In Belgium, vitamin K antagonists are
- Acenocoumarol under the Sintrom® brand
- Phenprocoumone under the Marcoumar® brand
- Warfarin under the brand Marevan®
and the direct oral anticoagulants are
- Apixaban under the brand Eliquis®
- Dabigatran under the Pradaxa® brand
- Edoxaban under the brand Lixiana®
- Rivaroxaban under the Xarelto® brand
Prevention of VTE after surgery
Prolonged immobility (eg flights of more than 6 hours) should be avoided for one month after the operation. Before the operation, the doctor will assess the risk of thrombosis based on your history, your risk factors and the type of procedure. If necessary, he will take preventive measures to avoid thrombosis. This can be done with medication or compression bandages or anti-thrombosis stockings.
Because anticoagulants prevent the blood from clotting, they increase the risk of bleeding. The doctor will therefore decide on the type of prevention based on the risk of possible thrombosis and the risk of bleeding (in patients with uncontrolled hypertension, for example).
Prevention of VTE in patients at risk
In patients with one or more of the risk factors for VTE and who are bedridden for more than 3 days, the doctor will consider prevention of thrombosis.
Prevention of VTE in cancer
Cancer patients have an increased risk of VTE. But cancer and its treatment can also lead to an increased risk of bleeding. That is why the doctor always weighs the possible risks against the benefits in each patient. Vitamin K antagonists can often interact with drugs used to treat cancer. A heparin is therefore a safer and more effective alternative.
In certain types of cancer surgery, the risk of VTE is particularly high: cancer of the lower abdomen, metastases, cancers of the tissue of the glands (adenocarcinomas), brain tumors and cancers that interfere with blood flow. In these situations, the prevention of thrombosis involves the administration of heparin.
Prevention of VTE during travel (by air)
Travelers (especially when the trip lasts longer than 6 hours) without known risk factors are advised to wear loose clothing, drink enough water and limit their alcohol and coffee consumption, and exercise the ankles to contract the calf muscles or to walk a little. High risk patients should follow the advice above and wear anti-thrombosis stockings. Considering the atmospheric pressure in the cabin of an airplane and the dryness of the air, the risk of VTE is further increased, it is better to be especially careful when traveling by plane, but these measurements are also valid for long trips by car, bus and train. Heparin can also be used in patients with known thrombophilia (coagulation disease) or who have a history of VTE. An injection half an hour before the flight provides 12 hours of protection. Aspirin is not recommended.
Prevention of VTE in Pregnancy
Pregnancy increases the risk of VTE. In principle, no prevention of thrombosis is necessary in healthy pregnant women (without risk factors). Prevention is indicated in case of complete immobilization, extensive lesion and more extensive surgery (cesarean section). In pregnant women who have a history of deep vein thrombosis (DVT) or pulmonary embolism or who have a permanent risk factor (for example, bleeding disease), the risk of (new) venous thrombosis is increased. In this case, however, the prevention of thrombosis is very specific and is the subject of discussion and planning in consultation with a specialist physician.
General advice
Try to quit smoking, try to maintain a normal weight and get enough physical activity.
Want to know more?
- Low molecular weight heparins – CBIP – Belgian Center for Pharmacotherapeutic Information
- Oral anticoagulants – CBIP – Belgian Center for Pharmacotherapeutic Information
- Stop smoking. It’s possible – Tabacstop
- Eating and gaining years of life is possible! (video) – CSS – Superior Health Council
- Physical activity – Eat Move – Health question
Are you looking for more specialized help?
- Smoking Assistance Center (CAF®) – FARES – Respiratory Affections Fund
- Tobacco specialists – FARES – Respiratory Affections Fund
- Find a registered dietitian – Professional Union of French-speaking dieticians
- Find a nutritionist doctor – Belgian Society of Nutritionist Doctors
Source