An abdominal aortic aneurysm (AAA) occurs when the walls of the main blood vessel that carries blood away from the heart (the aorta) are bulging or dilated. It is located in the abdominal area. Aneurysms can also occur in other areas of the aorta, but the abdomen is the most common site. AAA can be repaired either through “open surgery” or with the use of an “endovascular stent graft" (Endovascular aneurysm repair = EVAR) Open surgery — Open surgical correction of AAA involves removing the section of the abdominal aorta that is dilated and replacing it with a prosthesis made of synthetic material (also known as a graft) that is sutured into place . This will allow blood to flow normally and the artery wall is used to cover the graft. Planned or elective surgery reduces the risk of rupture of large asymptomatic AAA.