Venous thromboembolism encompasses deep vein thrombosis (DVT) and pulmonary embolism (PE) [1]. Other venous thrombotic occlusion like superficial vein thrombosis, thrombophlebitis, cortical vein thrombosis, hepatic nonocclusive disease, portal vein thrombosis, mesenteric venous thrombosis, splenic vein thrombosis, upper extremity venous thrombosis, are not included in the same category by international societies including American college of chest physician, American college of physician, European society of cardiology, European respiratory society, European society of Haematology, due to the significant mortality and morbidity caused by pulmonary embolism and lower extremity deep vein thrombosis [2-6].