This surgery is needed to prevent the rupture of the abdominal aorta. The aorta is a large artery that carries blood away from your heart to the lower part of your body. An aneurysm happens when the aorta becomes weak, like an old garden hose that starts to wear out, and suddenly can rupture or break. The surgery is done to prepare the rupture from happening because people can lose a lot of blood very quickly. The surgery takes place in the abdomen, not in the chest like an open heart. The surgeon opens the abdomen and then repairs it using a graft that looks like a hollow tube. This is almost the same as repairing a garden hose. The bad section is taken out and replaced with a new section.