Wondering about exchange size after double mastectomy with tissue expanders in filled to 420 cc causing back pain from surgery?

You deathly want to consider implant size based on your back history. Implants are heavy and can aggravate your symptoms. Unfortunately there's no way to gauge will affect your back. Be conservative with your choice and time will tell how your back will respond

Sometimes tissue expanders can cause back pain,. This may be due to the stretching of the tissues.  As for the type of implants to be used in the exchange, it really depends upon your anatomy and the volume you desire.