Aortic aneurysms in systemic lupus erythematosus: a meta-analysis of 35 cases in the literature and two different pathogeneses.

Background: Aortic aneurysms including dissection are uncommon complications of systemic lupus erythematosus, but the incidence has been increasing with an improved prognosis for this disease. However, the mechanisms contributing to aneurysm formation in systemic lupus erythematosus have not been fully clarified.

Methods: A meta-analysis of published cases was conducted to clarify the patient characteristics that may contribute to aneurysm formation in systemic lupus erythematosus. A search of relevant studies published over the past 40 years (1969-2008) was carried out in the publications on aortic aneurysms with systemic lupus erythematosus, and 35 cases were identified. The contributing factors to aneurysm formation as well as the patient prognosis were searched for sex, age, duration of corticosteroid treatment, aneurysm site (thoracic and/or abdominal), mortality, evidence of atherosclerotic involvement, and presence or absence of an operation, rupture, dissection, cystic medial degeneration, vasculitis, and hypertension. Each of these factors was assigned to each point score. Based on the point scores, a statistical analysis of rank correlation was thereafter performed.

Results: The factors correlating with the presence of thoracic or abdominal lesions differed significantly. The presence of thoracic aneurysms correlated with dissection and cystic medial degeneration, whereas abdominal lesions correlated with the finding of atherosclerosis. Thoracic lesions showed a high rate of death, while abdominal lesions were associated with a relatively favorable prognosis. Abdominal lesions were related to the duration of steroid therapy. The other correlations among the various factors were also evaluated, with the finding of cystic medial degeneration associated with vasculitis.

Conclusion: Two principal patterns emerged from this analysis. One was the fatal nonatherosclerotic thoracic aneurysm which was associated with cystic medial degeneration and probably due to vasculitis. The other was atherosclerotic abdominal aneurysm which was complicated by long-term steroid treatment and it showed a relatively favorable prognosis.