I know this is not really an answer to your question (which i doubt actually exists) but if your "friend" wants non-necessary non-urgent surgery in my opinion they shold pay for it (dont even get me started on being happy with what you've got) There are always risks with surgery and coming from someone who has had to have a lot of surgical procedures, i can't understand why anyone would wilingly put themlves through it, if they are well.
there has been a lot of stuff in the news lately about peple having botched cosmetic surgery abroad, and the NHS refusing to pick up the pieces (sometimes quite literally) because they have effectively gone private for it.
I suppose i would just urge your friend to be happy with what they have, and count their blessings tey dont actually HAVE to hve surgery to stay alive!