Perianeurysmal retroperitoneal fibrosis. An unusual cause of renal failure.

Retroperitoneal fibrosis causing ureteral obstruction in association with an abdominal aortic aneurysm has been reported infrequently. However, the clinical presentation of patients with this entity and the histopathologic findings at surgery are similar to those in patients with idiopathic retroperitoneal fibrosis. We describe a patient with perianeurysmal fibrosis and bilateral ureteral obstruction who presented with severe renal failure. The diagnosis of an abdominal aortic aneurysm with perianeurysmal fibrosis was made only at the time of surgery to repair bilateral ureteral obstruction. Previous case reports of perianeurysmal fibrosis are reviewed, and possible pathogenetic mechanisms are discussed. It is important to consider the presence of an occult abdominal aortic aneurysm in patients suspected of having retroperitoneal fibrosis because of the serious prognostic and therapeutic implications.