The femoral vein is the main drainage of the lower limb, and accompanies the femoral artery.
Origin and course
In the distal adductor canal, the vein is posterolateral to the femoral artery. Proximally in the canal, the vein lies posterior to the artery in the distal femoral triangle and medial to the artery at the base of the triangle.
The vein is between the femoral artery and femoral canal and therefore occupies the middle compartment of the femoral sheath.