<prompt> Most common cause of abdominal aortic aneurysm is:TraumaVsculitisSyphilisAtherosclerosis  <response>: 90 all abdominal aortic aneurysms are related to atherosclerotic disease and most of these aneurysms are below the level of renal arteries. Aneurysm: permanent and irreversible localized dilatation of blood vessel with at least 50 increase in diameter Ectasia: dilatation 50 of normal diameter AAA abdominal aortic aneurysm is diagnosed if diameter 3 cm in males or 2.6 cm in females MC location: Aorta Iliac Popliteal Femoral AIPF MC site of extra-cranial arterial aneurysm is infrarenal aorta MC site of peripheral aneurysm: Popliteal aneurysm Degenerative aneurysms caused by atherosclerosis are MC AAA 90 Width of aneurysm is most important predicting factor of rupture. Juan Parodi introduced endovascular aortic aneurysm repair EVAR.Classification True all three layers of vessel are involved, false do not have all three layers of vessel Infected mycotic aneurysm are false aneurysm Dissecting aneurysm dissection with aneurysmal dilatation of false lumen Fusiform symmetrical enlargement involving whole circumference of artery Saccular affect only part of the arterial circumference have higher risk of rupture 