Hello Helene,
I wish I had the answer for you, but I have had the same kind of pain for some time. I had my esphagectomy mid-2005. The pain came later - maybe a year or so. Since then I've seen local pain specialists as well as a doctor at the Cleveland Clinic. The local guy tried several kinds of nerve blocks but nothing has worked. (The trip to Cleveland was worse than a waste of time and gas. I was treated like a number, not worth the doctor's time. And he was supposed to be the "Best".)
I usually answer posts if I can give encouragement or information. In this case I can't, but I am very interested in what you find. I hope you find the answer.
Good Luck, KEEP MOVING, and Laugh Much,
Steve