Number 1, get another opinion. Number 2, the kidneys are upsteram of the liver, anytime you help the liver you automatically help all organs upstream of the liver, ie: kidneys.
I've seen it go both ways. I've seen them kill the kidney surgery folks and I've seen it save them. It depends on what the problem is. Another opinion is called for.
As long as the guys still alive get to work on the liver. That HAS to help the kidneys.
What are his symptoms??? How many drugs do they have him on???