Will acne affect FTM top surgery?

Antibiotics are used around the time of surgery which will clear you acne most likely.  Acne by itself will not contraindicate your surgery.

The presence of acne should not affect your ability to have surgery. If it does flare and there is a very large area of inflammation or an abscess, this may cause a delay in your surgery, but a small amount of acne should not disrupt your surgery. We mainly worry about acne and any acute flares in the setting of putting an actual prosthesis such as an implant into the body, so in this case that is not an issue. 

It would depend on the severity of the acne, as well as the location of the acne on the chest wall.  Best wishes.

Testosterone therapy can cause acne breakouts on the face, back and/or chest. This occurs because of the thickening of the sebum in the oil glands and the bacteria that love to live in that sebum. In my opinion, that can not be good for wound healing and may increase the infection rate after surgery. To avoid this problem, my patients with acne receive skin and oral anti-acne medications before surgery. Ask your surgeon about clearing your acne before surgery.