I would go to a Dr. that would take the leads out if I were you. I don't understand why they left them in, in the first place. If you don't want to have another put in, there is no reason to have the leads left in place. I had mine taken out after several months when the Dr. done another back surgery and my problems are all gone. With the puss and all, it is plain to see he can't leave it in. It just has to be the reason for infection.

In my case, the surgeon did tell my family, if it was to close to my spinal cord he would not remove them. I was fortunate, and he removed them. It was another doctor though. He did contact the one that put it in before, he removed the leads. They do have to be careful or you could become paralzed.
I have never heard of a case quit like your husbands, but you can become allergic to the leads where they join the battery. That was my big concern. I too am allergic to metals. I really feel for your husband. Good luck having this taken out.
Blessings,
Billie