I also have an AA, mine only measures 4.0. I also have/had bicuspid aortic valve disease. So I've always had several factors weighing in on when we would go in surgically to correct. However, the thought was we would go in once the AA hit 4.5. However, I got endocarditis in 2012 and because of treatment failure on antibiotics, I had to have open heart surgery to clean out the infection and replace my aortic valve. Due to the infection, I could NOT have the aneurysm repaired.
With all that said, I have not had the surgery you are speaking of, but have had open heart surgery. I was 37 at the time. I went home 4 days after surgery. Was up moving around once home. I walked up a flight of stairs at 3 weeks pot op and ran a mile at 7 weeks post op. Due to my age and fitness level, I did not need cardiac rehab, but most do. Most important advice I can give post op is to stay on your pain medication regimen. I set an alarm to wake me every 4 hours to take my meds, even in the middle of the night. You need the meds to move around and you need to move around to heal :)