Retroperitoneal fibrosis and chronic periaortitis: a new hypothesis.

The etiology of retroperitoneal fibrosis (Ormond's disease) has still not been clarified. A new hypothesis postulates chronic fibrosing periaortitis. Atherosclerosis of the abdominal aorta and plaque rupture lead to the liberation of oxidized lipoproteins through the adventitia into the periaortic fatty tissue. This results in a chronic inflammatory process. In support of the periaortitis hypothesis is our finding that 9 of 14 consecutively studied patients with retroperitoneal fibrosis had either proven atherosclerosis of the abdominal aorta or a high probability of this in view of multiple vascular risk factors. No patients had received previous methysergide medication.