Heart surgery. Harvested vein (bright red, upper right) being sewn (sutured) to the wall of the main body artery (the aorta). This is coronary artery bypass graft (CABG) surgery. The vein has been removed from elsewhere in the body (normally the legs). The other end of the vein will be attached to one of the coronary arteries that normally supply blood to the heart. The grafted vein will then bring blood to the heart, bypassing a blockage in the coronary artery. Such blockages arise from atherosclerosis, the build- up of fatty deposits, including cholesterol, on the lining of the arteries.