Heart surgery leg scar. Metal staples being used to repair a surgical wound in the leg of a heart bypass surgery patient. The incision was made to harvest leg veins to use as grafts for the heart. The leg veins were used to create new heart veins to restore blood flow to the heart muscle. The grafts are bypassing blockages in the coronary arteries of the heart. This sort of blockage is usually due to fatty deposits on the artery walls, a condition known as atherosclerosis. Coronary arteries perform the vital function of supplying blood to the heart. The veins harvested here were from the knee area.