The spectrum of chronic periaortitis.

A review of the histology of 440 sections of atherosclerotic aortas and arteries showed that 85% contained advanced atherosclerotic plaques. Of these, 92% showed some degree of adventitial inflammation with subclinical chronic periaortitis in 49%. A review of 20 cases of clinical chronic periaortitis, which included 12 cases of inflammatory aneurysm and 8 cases of idiopathic retroperitoneal fibrosis, showed that there were no significant differences between them apart from an increase in aortic diameter in the former. The term chronic periaortitis is appropriate for the spectrum of subclinical and clinical forms of chronic adventitial inflammation associated with advanced atherosclerosis and medial thinning.