Abnormalities of the aorta and vessels that supply blood to the brain may need to be intervened upon, especially if there are symptoms involved. Other indications for either percutaneous or surgical repair/replacement include absolute size, rate of increasing size, co-morbid conditions (i.e aortic stenosis) or if you are already undergoing open heart surgery for other reasons (i.e. repair of other valves). Because you have a known dilation of your aorta, this should already be followed on a regular basis by your cardiologist.
I forgot to mention that the report says my aortic arch is also aneurysmal. Could this have anything to do with the left vertebral artery being narrowed?
Thanks again for any information.