Symptoms
The possible symptoms and signs of deep vein thrombosis include:
- Pain or cramping in the legs
- Swelling (edema), feeling of tension
- Warmth sensation, overheating
- Reddish to blue-purple discoloration of the skin
- Increased visibility of the superficial veins
The symptoms are rather nonspecific. Deep vein thrombosis may also be asymptomatic and discovered by chance. A deep vein thrombosis can lead to a life-threatening pulmonary embolism and must therefore be immediately medically clarified and treated. A pulmonary embolism manifests itself, among other things, in shortness of breath, chest pain and a rapid heartbeat. Another complication is postthrombotic syndrome.
Causes
Deep vein thrombosis is caused by the development of a blood clot (thrombus) in the large veins of the legs or in the pelvic area. This blocks the flow of blood from the periphery back to the heart. In pulmonary embolism, the blood clot breaks loose and travels to the pulmonary arteries as a so-called embolus. Several risk factors exist. These include (selection):
- Immobilization, bed rest, paralysis.
- Oral contraceptives, hormone replacement therapy.
- Surgical procedures, operations, for example, a joint replacement.
- Injuries, fractures
- Pregnancy
- Overweight, obesity
- Sitting for long periods of time, for example during air travel.
- Smoking
- Cancers
- Heart failure
- Hereditary predisposition, thrombophilia
- Age
- Deep vein thrombosis in the patient history.
Diagnosis
Diagnosis is made in medical treatment based on the patient’s history, clinical picture, with scores, laboratory tests (D-dimers) and with imaging techniques (e.g. ultrasound, MRI). Leg pain and swelling may have several other causes, for example, phlebitis, infection, or venous insufficiency.
Drug treatment
Deep venous thrombosis has traditionally been treated with heparins and vitamin K antagonists. Today, direct oral anticoagulants (DOAKs) are also available for this purpose. After diagnosis, most patients can be treated on an outpatient basis. The usual duration is three (to six) months; an extension may be necessary. Depending on the agent, initial therapy with a low-molecular-weight heparin may be prescribed. Bleeding is the most common adverse effect. These can be reversed with antidotes if necessary. Low-molecular-weight heparins activate antithrombin, which in turn inhibits clotting factor Xa in the blood coagulation cascade. The drugs are usually injected subcutaneously. Unfractionated heparin is used less frequently today:
- Dalteparin (Fragmin)
- Enoxaparin (Clexane)
- Nadroparin (Fraxiparine, Fraxiforte)
- Related agents: fondaparinux (Arixtra).
Vitamin K antagonists inhibit the formation of blood clotting factors. The dose is adjusted individually and must be monitored continuously with prothrombin time. The effects occur with a time delay and are not immediately reversible after discontinuation:
- Acenocoumarol (Sintrom).
- Phenprocoumon (Marcoumar)
- Warfarin (Coumadin)
Factor Xa inhibitors directly inhibit blood clotting factor Xa and have a rapid onset of action. They quickly lose their effects after discontinuation or when the drug is interrupted. They do not need to be injected and no monitoring or dose adjustment is required:
- Apixaban (Eliquis)
- Betrixaban (Bevyxxa)
- Edoxaban (Lixiana)
- Rivaroxaban (Xarelto)
Thrombin inhibitors inhibit the protease thrombin, which converts fibrinogen into fibrin. Dabigatran is taken in the morning and evening in the form of capsules:
- Dabigatran (Pradaxa).
Fibrinolytics (thrombolytics) are used less frequently today. Accompanying drug treatment is usually compression therapy. The aim is to relieve discomfort and prevent post-thrombotic syndrome.
Prevention
- Physical exercise
- Weight reduction
- Quitting smoking
- Drink enough fluids
- Influenceable risk factors
- Compression therapy
- Drug prophylaxis