Ascending aorta involvement is the commonest site of which aneurysm -

Direct lines… “The obliterative endarteritis characteristic of late-stage syphilis shows a predilection for small vessels, including those of the vasa vasorum of the thoracic aorta.” Atherosclerosis affects abdominal aorta most commonly. Traumatic aneurysm can affect any site of the aorta. Berry aneurysm affects the circle of Willis.