This may be difficult as many teaching hospitals require the man/woman-power in the OR. Also you would have to arrange for your own malpractice, state license, etc. You best find a program with strong pain department or one in the same city. Not to mention this is about the same time you have to worry about your board exam, fellowship applications. Hopefully you have a good secretary in your department to help you with arranging an elective outside of your training hospitals.