Preparation for mastectomy + DIEP + potentially port removal

For the short read:

What exercises for PRE-surgery do you recommend? I have about 2 months time, am 45 and generally fit except for limited mobility in one arm due to a pesky port that won't ever heal properly (see deep read below if interested).

For the deep read:

So I hear this is a 10 hr surgery with my arms up over my shoulders and people leaning over them. Obviously lots of incisions and wound care to follow as well as time appropriate physio and exercises.

I'm still 2 months out from surgery and would like to be as prepared as possible since I've previously suffered shoulder bursitis and subsequent frozen shoulder on both sides (at different times fortunately!) that lasted many many months (less the 2nd time as I could feel it coming on).

Any pre-surgery exercises to recommend?

I also have had problems with scar healing. My port insertion was the first time I've ever been cut and stitched up. I had it first become dehiscent, then redone 6 weeks later, then lots of spitting sutures. After another 8 weeks the skin was irritated from taping so stopped that. But in a week, the scar continues to widen without taping and is now 2cm wide! Have now started back on with stratamed and taping but using a gauze over the wound because it now got a bit of exudate. Yes, nurses and doctors monitor it, I have suitable antibiotics on hand, but since they saw how bad it got last week I've been told to be extra vigilant and go straight to ED with a low tolerance of anymore funny business or temperature of course.

So stretching back on the port side is currently difficult.

Many many thanks for all you lot helping each other out ❣️