by Dr Deepak Williams (North Coast Vascular)
DVT is a common condition that is increasing with the aging population. It usually occurs in the deep veins of the lower limb and occasionally in the deep veins of the upper limb. DVT has a significant effect on the patient’s life if not treated properly.
The causes of DVT can be classed according to the Virchow’s Triad Immobility this can be due to prolonged travel by air, road or rail, hospitalisation, surgery, fracture requiring a cast and post-partum.
Hyper coagulator ability is the coagulation of blood faster than usual caused by medication such as birth control pills which contain estrogens, smoking and a genetic predisposition eg Factor 5 Leiden positive, polycythaemia or cancer.
Trauma to the Vein is usually due to fracture to the leg, bruising or compilations after invasive procedures on the veins eg varicose veins surgery, placements of catheters or lines through the veins. The symptoms of DVT include pain, swelling, warmth and redness of the limb. Symptoms may mimic infection or cellulitis. Chest pain and breathlessness would indicate pulmonary embolism.
Diagnosis is made with ultrasound scanning which locates the site, position of the thrombosis and can occasionally differentiate between fresh and old thrombosis. D-dimer test used to determine if a blood clot exists. D-dimer is a chemical that is produced when a clot actually dissolves. If the test is negative then no blood clot exists; it may give a false/positive. The other tests include direct venography or CT venograms.
Treatment of DVT the mainstay of treatment of DVT is still anticoagulants and compression. DVT in the tibial veins can be treated with Aspirin and compression; however thrombus requires anticoagulation unless there is a contraindication such as recent surgery or haemorrhagic stroke etc. Anticoagulants commonly used are Warfarin, Apixaban, Rivaroxaban, Xarelto and Dabigatran.
Treatment of uncomplicated DVT must continue until there is no evidence of a clot and that the clot has dissolved completely.
The role of surgery in DVT is increasing, the commonest indication for surgery is May–Thurner syndrome where the patient would benefit by having thrombolysis done in the first instance and then followed up with a venography and stenting of the left common iliac vein. There is increasing use of thrombolysis in acute DVT where it involves a short segment of the vein. Thrombectomy is rarely done.
Complications of DVT – Pulmonary Embolism (PE) is a major complication of DVT. It presents with chest pain and shortness of breath. Any patient who is at a high risk of PE should have an inferior vena cava filter placed in situ, especially patients undergoing thrombolysis, surgery or with a past history of embolism with new DVTs.
Post Phlebitic syndrome is when the affected leg becomes swollen, painful, skin changes and ulceration occurs.
Prevention is of prime importance. Continuous use of compression stockings and prophylactic anticoagulation after surgery or use of a filter with compression in patients that are undergoing long procedures has reduced the incidence of DVT in hospital patients. During long distance travel it is advisable to walk regularly and wear compression. Compression also helps to prevent future DVT, especially those with history of DVT or those who are immobile.
The whole idea is to prevent the clot from forming in the first place but if it does then to institute prompt therapies to prevent it increasing or travelling to other circulatory locations like the pulmonary circulation. Blood is a funny creature if it is not moving it clots; hence keep it circulating and take care of your vascular self.