The etiology is somewhat different I believe, Aortic root dilatation or ascending aorta is classically seen in tertiary syphilis involving the Vasa vasorum leading to stenosis of the lumen and atrophy of the wall. As far Aortic aneurysm, (classically known as Abdominal Aortic Aneurysm) the etiology is a dilatation primary d/t Atherosclerosis.
aortic root dilation is seen in patients with marfans, aortic root dilation can lead to dissection. We can help prevent dissection by giving ARBs which help to neutralize the increased TGF-B signaling. Hope this helps.