Elective surgery while breast feeding not recommended!
Others have said it quite well, and I will add my recommendation to theirs--do not expose your baby to any kind of medications or anesthetic drugs that might become part of your breast milk. Sure, you can pump and store, but you can also wait, make sure you are at your ideal post-baby weight, and proceed when you are finished breast feeding.
The fact that you are asking means you are a mom who understands there may well be some concern here. Follow that awareness, and those who recommend...