[Atypical initial manifestation of abdominal aortic aneurysm. The causes of diagnostic and therapeutic errors].

Initial manifestations of an abdominal aortic aneurysm may, depending on its site, morphology and direction of expansion, imitate numerous other intraabdominal diseases, but also lesions of peripheral vessels, vertebral column and spine. In this way they may give rise to errors of diagnosis and treatment. An abdominal aortic aneurysm should be considered especially in case of unclear gastrointestinal bleeding or abnormal intestinal passage (ischaemic colitis; mechanical displacement or compression of the duodenal-jejunal flexure and of the small-intestinal mesentery). In case of massive or recurrent gastrointestinal bleeding, especially in combination with a septicaemia, an aorto-intestinal fistula should be considered in the differential diagnosis. Radicular compression syndrome may be caused by an aortic aneurysm which is usually contained and predominantly suprarenal (to be considered especially once a herniated disk has been excluded by computed tomography). The same is true for unclear bone defects of the lumbar vertebrae (erosion by a penetrating aneurysm). Noninvasive methods, such as upper abdominal sonography, computed tomography and relatively minor invasive transvenous digital subtraction angiography now predominate in the definitive diagnosis of abdominal aortic aneurysm.