An aneurysm situated in the stomach (stomach). An aneurysm is a localized widening (dilatation) of an artery, vein, or the heart. On part of an aneurysm, there was usually a bulge in addition to wall surface is weakened and may also rupture. Your message "aneurysm" originates from the Greek "aneurysma" meaning "a widening." An aneurysm may involve the aorta, the greatest artery in your body, since it courses down through stomach. Due to the great amount of blood moving under ruthless into the aorta, rupture of an abdominal aortic aneurysm is a surefire disaster.