I'm scheduled for the keyhole/peri on the 26th. Trouble is, they say not to do any heavy lifting after surgery for a while. I'm afraid I'm going to lose some of the muscle I've built up by lifting weights every day. I want to continue my regimen as soon as possible after surgery, but I don't want to stretch the scars or hurt anything. How long should I abstain from working out? Are there any exercises I can do for my biceps that don't have a risk of stretching the scars? I'm going to ask my surgeon about this, but any input would be helpful.

i had the peri/keyhole procedure done and the surgeon said i couldn't go back to the gym for at least 4 weeks. Basically the marker is pretty much when you can reach up/out without feeling like you are stretching the muscles or tissue in your chest.

When i had my revisions done- 6 mths later,  i had to wait 2 weeks before working out again. I would suggest using a routine that isolates your biceps for the first few workout sessions, so you don't risk  stretching the scars and/or the areola.

Congrats on the surgery.

Make sure to keep up on your protein intake and get enough Calories.  That should retain them.  I didn't start losing muscle until recently (been on hormones about 17 months) and that was due to me losing weight really fast.  So, if I can keep my muscles on estrogen, I don't see why you couldn't.

Don't fret over it. You aren't going to lose that much muscle mass within a month, not so much that it would put a dent in your hard work. Just eat well and take it slowly. Like you said, you don't want to damage the results of your surgery for the sake of muscle which you can build up anyway after healing.