Aortic aneurysm

Aortic aneurysms are diseases of elderly with risk factors for atherosclerosis, like smoking, hypertension, and dyslipidaemia.

We distinguish two types of aortic aneurysms depending on the affected part of the aorta, thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA). 90% of cases are abdominal. An aortic aneurysm is defined as a dilation > 50% of the normal diameter, or > 3 cm.

Aortic aneurysms are problematic because they can rupture, which kills most of affected people within minutes or hours, and because they can compress other structures. These aneurysms typically grow slowly, but the risk of rupture and compression increase with the size.

Pathology

Degeneration of elastic and collagen fibres, as well as atherosclerosis, causes the formation of the aneurysm. Degeneration occurs due to mechanical stress due to hypertension and due to activation of proteases like collagenase, elastase, matrix metalloproteinase, and plasmin.‎