As the femoral artery can often be palpated through the skin, it is often used as a catheter access artery. From it, wires and catheters can be directed anywhere in the arterial system for intervention or diagnostics, including the heart, brain, kidneys, arms and legs. The direction of the needle in the femoral artery can be against blood flow (retro-grade), for intervention and diagnostic towards the heart and opposite leg, or with the flow (ante-grade or ipsi-lateral) for diagnostics and intervention on the same leg. Access in either the left or right femoral artery is possible and depends on the type of intervention or diagnostic.