cardiovascular disorders
Deep Venous Thrombosis (DVT)
Introduction
Deep venous thrombosis (DVT) is clotting of blood in a deep vein of an extremity (usually calf or thigh) or the pelvis. DVT is the primary cause of pulmonary embolism. DVT results from conditions that impair venous return, lead to endothelial injury or dysfunction, or cause hypercoagulability. DVT may be asymptomatic or cause pain and swelling in an extremity; pulmonary embolism is an immediate complication. Diagnosis is by history and physical examination and is confirmed by objective testing, typically with duplex ultrasonography. D-Dimer testing is sometimes used when DVT is suspected; a negative result helps to exclude DVT, whereas a positive result is nonspecific and requires additional testing to confirm DVT. Treatment is with anticoagulants. Prognosis is generally good with prompt, adequate treatment. Common long-term complications include venous insufficiency with or without the post-thrombotic syndrome. 5% of DVT cases) ( General references ). Lower extremity DVT is much more likely to cause Pulmonary Embolism (PE) (PE), possibly because of the higher clot burden. Approximately 90% of proximal DVTs involve the femoral or popliteal veins and 10% extend more proximally to involve the iliofemoral veins ( About 50% of patients with DVT have occult pulmonary emboli. 