You will not just go to any dialysis center and said:"I want a dialysis today." You have to go to a doctor first, a lot of tests, and I won't be surprised it will cost you a few more thousand just to get it started.
Go to any dialysis facility locally and ask about their procedures.
I don't think there will be visa problems just because of this; you don't have to tell her medical conditions. But just make sure long distance flights will do no harm to her.