How does an ascending aortic aneurysn differ from a descending aortic aneurysm?

Couple of things. Ascending aortic aneurysms occur anywhere from just after the heart to just after the takeoff of the blood brain vessels. In descending aneurysm, the site is any of the remaining aorta. This becomes complicated because one type can also turn into the other. Generally speaking, ascending aneurysms are usually operated on, and descending are usually medically managed. Complicated topic.