denial of procedure

I am needing to have weight loss surgery done with my doctors approval. My insurance company does NOT approve them no matter what. My question is this, is there a law in Oregon that can force them to do the surgery for someone that is morbidly obese? There is a law in California that does force health insurance companies to pay for the surgery regardless if they cover it or not. It really surprises me that health insurances are not covering this operation nowdays when Medicare has been approving them. Thanks in advance for any information that you can give me.

Leeann Vaughn