second, elective mastectomy

I’m having a second, elective mastectomy next Wednesday. I had my first one two years ago, and had significant arm problems, and severe cording, due to removal of lymph nodes. However, after months of physio, all is well now. The cording flares up from time to time. The surgeon has said that I have axillary breast tissue, which he will also remove during this op. There’s a significant fatty lump under my arm, it is a little unsightly. I am a little concerned that my arm movement may well be compromised again! I am a musician. Has anyone undergone removal of this tissue and had problems? Many thanks.