Femoral vein
In the human body, the femoral vein is a blood vessel that accompanies the femoral artery in the femoral sheath. It begins at the adductor hiatus (an opening in the adductor magnus muscle) and is a continuation of the popliteal vein. It ends at the inferior margin of the inguinal ligament, where it becomes the external iliac vein. The femoral vein bears valves which are mostly bicuspid and whose number is variable between individuals and often between left and right leg. Drainage. Several large veins drain into the femoral vein: Clinical significance. Occlusion of the femoral vein can  be life-threatening due to its size. For example, deep vein thrombosis of the femoral vein can cause pulmonary embolism, with a higher risk when the thrombus is located in the common femoral vein than in the subsartorial vein. The femoral vein is often used to place central venous lines. This is associated with a significant risk of infection. The practice of delivering recreational drugs intravenously using the femoral vein is relatively common amongst injecting drug users (IDUs).