Background: The majority of ascending aortic aneurysms cannot be related to any specific etiology and should be qualified as idiopathic. The incidence of this disease is increasing in the population of the developed countries but its pathobiology is poorly understood.
Aim: This article is reviewing the publications concerning the pathobiology of idiopathic ascending aortic aneurysms.
Sources: A PubMed search on articles published in English or French, between January 1965 and December 2007, on key-words << aortic root >>, << ascending aorta >>, << aortic arch >>, << thoracic aorta >>, << aneurysm >>, << dilatation >> and << dissection >> was undertaken. Articles on aneurysms related to inflammatory and infectious diseases, congenital or genetic syndromes were excluded.
Results: The presented data suggests that destructive remodeling of the aortic wall, inflammation and angiogenesis, biomechanical wall stress, and molecular genetics are relevant mechanisms of idiopathic ascending aortic aneurysm formation and progression.
Limits: Sparse data available from few direct studies offer limited knowledge on pathobiology of idiopathic ascending aortic aneurysms.
Conclusion: A more intimate knowledge of the triggers and perpetrating factors of this disease might offer new diagnostic and treatment options.