Vascular Aneurysms and Dissections

Aortic aneurysms (AAs) and dissections are rare but important causes of cardiovascular morbidity and mortaLity. Aneurysms can result from genetic predisposition in a MendeLian pattern in the young and old, as well as classical cardiovascular risk factors in older individuals. Despite elastic fiber fragmentation and pools of mucoid material being present in histopathologic specimens, in experimental murine models the causative mechanism for aneurysm progression appears to be altered transforming growth factor beta (TGF-β) activity driving functional deficiencies, rather than a primary structural derangement. Altered TGF-β activity has now been documented in human syndromic aneurysmal disease and in human nonsyndromic aneurysm. This article will describe the diseases and histopathologies of AA. It will also describe the mechanistic alterations in the TGF-β pathway as a result of genetic mutations and how these perturbations inform our understanding of AA development and progression.