Isolated periaortitis

Isolated periaortitis is a non-aneurysmal form of chronic periaortitis.

Pathology

Periaortitis may be a local immune response to antigens like oxidized-low density lipoproteins and ceroid found in the atherosclerotic plaques of the abdominal aorta. The disease tends primarily to involve the vascular structures causing stenosis of the major branches of the abdominal aorta (eg, celiac trunk, SMA, renal arteries).

Clinical features

• pain
• fever
• fatigue
• weight loss
• anaemia
• mesenteric arterial ischaemia: abdominal pain, diarrhoea, and gastrointestinal hemorrhage 
• renal artery stenosis: renovascular hypertension 
• vascular impairment depending on which other vessels are involved.

Radiographic features

CT

• low-density periaortic enhancing mantle of soft tissue
• abdominal aorta and its major branches appear to be narrowed.

MRI

Signal characteristics of affected regions include:

• T1: hypointense  
• T2: hyperintense 
• C+ (Gd): intense enhancement 

PET

PET scan with 18F-fluorodeoxyglucose is an excellent tool in assessing the metabolic activity of the mass, detecting other sites of inflammation and disclosing infectious or neoplastic lesions with which periaortitis may be associated.

ManagementTreatment and prognosis

Steroids are usually effective and induce remission of the clinical symptoms, normalization of the acute-phase reaction, reduction in size of the retroperitoneal mass and also resolution of the obstructive complications. A number of immunosuppressive drugs, such as azathioprine, cyclophosphamide, and methotrexate, have been used as steroid-sparing agents or in patients not responding to steroids alone or when steroids cannot be tapered.