Artificial aorta. Coloured chest X-ray of the top part of an artificial aorta (pink, arching from upper left down to bottom centre). The surgery was required to repair an aortic aneurysm (swelling). The whole of the upper aorta, and the aortic valve to the heart (green ring, upper left) have been replaced. The heart is not clearly seen, but occupies most of the lower left of the image. The swelling of an aneurysm arises from arterial blood pressure acting on a weakness in the artery wall. It can arise from accumulation of fatty deposits on the wall (atherosclerosis). Rupture of an aneurysm is often fatal, so surgical repair is required before this happens.