AAA and Visceral Aneurysms

An aneurysm is a section of artery which is dilated in comparison to its original vessel diameter. By definition this is generally accepted as dilatation by at least one and a half times the normal vessel diameter. Therefore aneurysms are defined by the artery affected rather than by absolute diameters. Aneurysms can be classified as either true or false. True aneurysms are those which are bound by all three layers of the artery (intima, media, and adventitia), whereas false aneurysms, also known as pseudoaneurysms, are bound only by adventitia. As an aneurysm enlarges, the risk of rupture increases, but for any given size, pseudoaneurysms have a relatively higher rupture risk when compared to true aneurysms of the same size.