Inflammatory abdominal aortic aneurysm and retroperitoneal fibrosis

Abstract

The inflammatory aneurysm of abdominal aorta (IAAA) accounts for 3-11% of all abdominal aortic aneurysms, and occurs predominantly in men. It has similar pathological mechanisms like idiopathic retroperitoneal fibrosis (IRF) and perianeurysmal retroperitoneal fibrosis (PRF), thus presenting the same non-specific systemic inflammatory disorder known as chronic periaortitis (CP). Recognition of CP early in its course is important in order to reduce morbidity due to complications, such as renal failure and mortality from aortic rupture. However, the initial symptoms of CP are non-specific, which makes early clinical diagnosis extremely difficult. Various studies have shown favorable outcomes following corticosteroid treatment in nearly 90% of patients. The positive effects of adding different immunosuppressants to corticoid therapy have established such "duo-therapy" as a durable treatment option. Also, cessation of smoking has a positive effect on disease course and it should be an integral part of every treatment regimen. Operative repair of the abdominal aortic aneurysm is considered to be the definitive treatment for IAAA. The effects of both open and endovascular interventions on the inflammatory component however remain unclear. Resolution of periaortic fibrotic tissue after surgery for IAAA is still debated. Some investigators have reported a complete resolution while the others have noted partial regression and even persistence of the inflammatory cuff. Current treatment strategies are based upon "the best available evidence'', mostly derived from clinical experience obtained by case series involving a small number of patients. Studies of a higher evidence level are very much needed to adjust our approach to such patients and to establish guidelines for treating this complex and serious disorder.