Something to be aware of in aneurysm measurements is that the MRI and Echo measure differently. One measures straight across the aorta and the other measures on the diagonal so will always have a higher number. So we can't compare the two and think our aneurysm size has had a sudden growth spurt.
My ascending aortic aneurysm is at 4.4, which is up from 4.3 two years ago. I expressed concern to my cardio and she said that amount of growth is insignificant. Another cardio described the aneurysm as "small".
I understand that aneurysm repair is a big surgery (and I don't know how long a repair is expected to last). I think unless there is another issue, a well regarded cardio surgeon will not repair the aorta at this size. Watchful waiting seems to be the protocol. I am 78 and am hoping I kick the bucket of some other issue well before I need this surgery.
I understand your concern and your desire to take control of the situation and just get it fixed. But I'm not sure getting it fixed at this stage is my best option. I wish you good health and slow growth to the aneurysm.