HI again Flora,
I'm just adding a little more of my "2 cents worth". I'm in the U.S. so I don't know anything about U.K. medical systems so I'm no help there.
But, my Pain Mgt. Dr. has told me that if I go for any invasive surgery she would recommend giving me a nerve block immediately before and after surgery to try to prevent spreading and/or flare up.
I get those anyway about every 2 weeks anyway for the pain management and so far it's working pretty well but that's just me.