[Inflammatory aneurysm of the abdominal aorta and ureteral obstruction]

The incidence of inflammatory abdominal aortic aneurysm (IAAA) is reported in between 5 and 15% of all cases of abdominal aortic aneurysms (AAA). As a diagnostic hint the CT- or MRI-scan shows the ureters typically displaced medially, caused by a simultaneously visible retroperitoneal perianeurysmal fibrosis. In IAAA, one has to expect about 25% ureteral congestion, uni- or bilateral. Since the probability of rupture of IAAA--in the natural course between 15 and 25% of the cases--does not apparently differ much from the arteriosclerotic AAA, the operative aorto-iliac reconstruction with bypass grafting is the only solution and procedure of choice. Postoperatively, renal insufficiency caused by congestion normalizes: long-term follow-up by CT-scanning demonstrates the regression of both retroperitoneal fibrotic process and ureteral entrapment. Therefore, the dangerous ureterolysis results to be unnecessary. Hydronephrosis due to ureteral obstruction following aorto-iliac bypass grafting, if progressive or symptomatic, should be treated first non-operatively by ureteral splint.