Hi I am sorry for all you have went and continue to go through. I am not that familiar with the pump but when I was at Cleveland Clinic and they were talking about possible treatments they said that the pump would be one of the last things they would want to try. I am not sure the possible side effects but if you are considering this I would research as much as you can and possibly get more then 1 opinion. I fear with any procedure or surgery the rsd going to that area as well.
I agree with others about looking into ketamine. Have you tried other meds? Have you looked into seeing a new doctor who deals with rsd? Sometimes a new approach can help.