Hi.
I believe this surgery will be less complicated than that of your double mastectomy, since this is just a matter of taking out the expander and replacing it with silicone. However, I would still expect some drains to be put just be sure there would be no unecessary fluid accumulation.
One factor that can influence the outcome of this surgery is whether you had radiation treatment. If you had radiation over the breasts, then this has a higher incidence of wound complications and infections.
Good luck with your operation and God bless.