Letter for Insurance Company

Does anyone have a sample letter from their PCP to their insurance company?? I have Empire BCBS and my claim is going in for review tomorrow. My regular doctor has only been seeing me for the last nine months, and I would like to supply her with a sample of what the insurance company typically wants to see from the physician. I am under the gun because of a change in insurance providers by my employer as of 9/01. If I can't get approval immediately and have my surgery as scheduled on 8/19, I will end up having to deal with Aetna...which I've heard can be difficult. Can anyone help me?