Are there any laws/rules that would keep a doctor from performing surgery on a family member?
To answer your question in short: I don’t think so.
That which makes this story so unusual is the commentary and the number of operations. For the doctor to say he married his wife for “potential” and then to go forth and operate on her eight times is unusual to say the least.
The questions raised include: Did she want any of this surgery? Is this coercion?
There is a difference between this and doing some surgery on your family member who actually wants the surgery for him or herself. As usual it is a matter of degrees and this story is over the top.