It is not uncommon that the nerve has to be sacrificed, in fact most that I talk to have had it cut. It is almost impossible to dissect around it and still get all the tissues that need to be removed. (They will remove the fatty tissues of the neck as well as the nodes.) The life long numbness as a result of this has not been a significant issue to me since treatment.
I also had what appeared to be an incomplete response to the radiation treatments (after having the maximum dose that my spinal cor could endure), but when the nodes were examined by the pathologist they were completely clean. This is not an uncommon issue/outcome when reading scans taken at the end of treatment. I do not regret getting the surgery, as I wanted to be sure that we had gotten it all. However any fistula which is still draining is not a good sign that the cancer has been completly eliminated. This is a gray area, as necrotic tissues left as a by-product of treatments can be producing some type of discharge or even infectious process. My surgery was 5 weeks after the end of radiation treatments.