Deep leg veins return blood directly to the heart and are in the center of the leg, near the bones. Superficial leg veins are just beneath the skin. They have less support from surrounding muscles and bones than the deep veins and may thus develop an area of weakness in the wall. When ballooning of the vein occurs, the vein becomes varicose. Perforator veins serve as connections between the superficial system and the deep system of leg veins.