What additional surgery would be needed to achieve a more symmetric, flat chest? (Photos)

It looks as toug you would get improvement with additional liposuction, including ulrasonic liposuction. It also depends on the looseness of your skin which would require an examination. Good luck.

Frankly, it doesn't look like you ever had gyno surgery or I wouldn't be seeing the fullness that I see. I would approach your case as if it was never done. This would remove all of the fullness in the various Zones on your chest and make for a masculine, even result.Yes, it's possible to deal with what you have easily.

I am sorry to hear about your concerns after previous chest wall surgery. Based on your photographs, I can understand your concerns regarding asymmetry.  Assuming you are at your long-term stable weight, or close to it, additional surgery will be necessary to improve symmetry and achieve more "flatness".  Although physical examination would be necessary to know for sure, it is likely that combination of direct tissue excision along with liposuction surgery will be necessary. Best wishes.

No two sides of the chest are exactly the same, and they certainly will not be the same after surgery. If you feel you need more work on one side, then that is something to review with your doctor in person.  Good luck.