Need advice on seeking a 'second opinion'.

My son was born with a birth defect that we were told would require two separate surgeries. The first surgery did not heal as they had planned, so he is now going to require a 3rd surgery with both his specialist and a plastic surgeon.

After seeing how horribly the first surgery healed, we have decided to seek a second opinion at one of the top children’s hospitals in the US. We are blessed with amazing insurance, but I am at a loss as to where to start with this.

How do you approach insurance companies about second opinions? How do they usually react? Do we need to prove that something was done incorrectly? (Which would be very easy, in our case) How do they handle travel?

I know that a lot of these answers will depend on our insurance… I am just looking to see what others experiences were when having dealt with things like this. Are there ways to approach this to make it easier on us?