This procedure involves repairing a weakened area in the abdominal aorta, the largest artery in the body. The weakened area is called an aneurysm, and it is caused by a weakening of the artery wall. During the procedure, a surgeon will make an incision in the abdomen
From Wikipedia
Abdominal aortic aneurysm (AAA) is a localized enlargement of the abdominal aorta such that the diameter is greater than 3 cm (1.2 in) or more than 50% larger than normal. An AAA usually causes no symptoms, except during rupture. Occasionally, abdominal, back, or leg pain may occur. Large aneurysms can sometimes be felt by pushing on the abdomen. Rupture may result in pain in the abdomen or back, low blood pressure, or loss of consciousness, and often results in death.