Depends where you live but find a thoracic surgery expert who does the surgery a lot, has a good record, and ask for their advice and action plan for your case. Preferably one at a large reputable hospital. My specialist told me that surgery is recommended when reaching 5.0 cm or higher but how fast the dilation increases might play into it.

Just as @23997929 said, find the best thoracic surgeon you can find and I would add a cardiologist who is an expert in aneurysms (it's not every cardiologist), in general as far as I know there are no alternatives for ascending aneurysms but open heart surgery, I had mine taken care of 5 years ago. How easy it is depends a lot on the person's general physical condition/fitness, other ilnesses, smoker or not, etc. Mine was fairly "easy", recovery was relatively fast (5 days in the hospital, returned to work after 3 weeks), but everyone is different. A good cardiologist and surgeon would be able to properly assess you and give you the proper advice, they take multiple factors into account to decide when surgery is recommended, size and shape of the anurysm, body size, family history, etc