Aortic aneurysm in patients with autoimmune diseases treated with corticosteroids

Aortic aneurysm is a rare but life-threatening cardiovascular complication in patients with autoimmune disorders. The purpose of this study was to clarify the characteristic clinical features and the pathological mechanism of aneurysmal formation in those patients treated with corticosteroids.

Among 429 patients operated on for abdominal aortic aneurysm during the past 10 years, six patients with autoimmune diseases treated with corticosteroids (one with progressive systemic sclerosis, one with rheumatoid arthritis and four with systemic lupus erythematosus) were reviewed retrospectively. Their data were compared with those of 391 patients with atherosclerotic aneurysms with no autoimmune disorders. The resected aneurysmal walls of the six patients were also compared histopathologically with those of the last six consecutive patients in the control group.

The average age of the patients with autoimmune disease was younger than that of the control group (53.8+/-16.6 vs 71.8+/-7.8 years; p<0.05). Patients with autoimmune disease had received long-term corticosteroid therapy for 15-32 years; mean 22.2+/-6.5 years. Pathological examination showed that the destructive change of the medial elastic lamina in the autoimmune disease group was wider than that in the controls. Most patients had no complications in the postoperative follow-up period (5.1+/-3.2 years), while one patient died of rupture of a dissecting aneurysm two years after operation.

Prolonged corticosteroid treatment probably plays a major role in the disintegration of connective tissue of the media, possibly together with primary aortic wall involvement and/or vasculitic damage in patients with autoimmune disorders, which can result in aortic aneurysmal enlargement.