The greater saphenous vein is an anatomically constant vein that is easily cannulated for emergency venous access. The saphenous vein at the ankle is constant, although it may be involved by varicose vein disease in elderly patients. Although the interosseus route is faster in children, this remains a useful route of access, especially because it is somewhat removed from the central area and thus out of the way of resuscitative attempts. Bony landmarks render the vein easy to find.

The greater saphenous vein at the groin is sometimes used for introduction of an extremely large catheter, such as a sterile oxygen flow catheter, through which blood and intravenous fluids can be infused rapidly in a patient with traumatic injuries. The techniques of saphenous vein cutdown at the ankle and the groin are described in this chapter. Alternatives are discussed in the references at the end.