Chronic pain after top surgery in 2005. What can be done to treat this?

I had double incision top surgery in 2005 and I have had chronic pain ever since. In the last two years it has gotten severe. It has been confirmed as nerve pain by nerve blocks but nerve blocks on last a week or two. Physical therapy has not been helpful. Is there anyone especially in MN who can surgically repair the nerve or cut it so that it is numb in that area? The pain is really debilitating.