The aneurysmal wall. The key to a subclassification of intracranial arterial aneurysm vasculopathies?

SUMMARY: The pathogenesis of intracranial arterial aneurysms (AA) has been debated for many years and still remains unclear, although these entities might pose life-threatening risks to the patient and understanding the disease is of utmost importance for choosing treatment concepts. Apart from the "classical" berry-type aneurysm, there are different other types of intracranial AA such as infectious, dissecting or giant, partially thrombosed aneurysms. From the clinician's perspective, the hypothesis that some of these intracranial aneurysms might be due to abluminal factors has been put forward for many years. Alterations of the vessel wall, either due to luminal or abluminal factors may be employed for an etiological classification of aneurysmal vasculopathies as will be discussed in this article. Moreover, regarding certain aneurysmal vasculopathies as an abluminal disease might alter current therapeutic strategies since therapy should not only aim at the intraluminal repair of the artery but may also target the vessel wall.