الفهرس 
ANATOMY A) The Veins of Lower ExtremityOnly 14 pages are availabe for public view
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Abstract
A
ccording to Virchow’s triad (decreased flow rate, blood vessel damage, and hypercoagulability) many conditions can lead to venous thromboembolism,some of them are inherited (thrombophilia), traumatic, infection, medical and malignancy.
In malignancy, there are some tumors associated with high risk of venous thromboembolism and others with low risk. The mechanism by which the deep venous thrombosis develop may be attributed to several factors released from tumor cells which causes increased hypercoagulable state.
During the course of treatment of malignancy there are some chemotherapeutic agents increases the risk of venous thromboembolism. Also patients receiving medication through central venous catheter, the catheter itself may precipitate thrombosis.
All patients undergoing major surgery for malignant disease should be considered for thromboprophylaxis with low-dose UFH, LMWH, or fondaparinux starting as early as possible for at least 7–10 days, unless contraindicated. Mechanical methods may be added to anticoagulation in very high-risk patients but should not be used alone unless anticoagulation is contraindicated
In cancer patients with acute venous thromboembolism long term treatment with low molecular heparin decreases the risk of venous thromboembolism than with vitamin K antagonists as treatment with vitamin K antagonists is associated with practical difficulties regarding drugs interaction, change in liver metabolism and adequate control of the dose with INR.