Medical Savings

I need to save more than £16000 for medical fees, but then my universal credit gets cut off? I'm on LCWRA, I'm completely unable to work and only expected to deteriorate further. It's been okay up to now as I've saved for things one by one and just spent years waiting for tests and treatments I need, but now I'm pretty sure this surgery will cost more than I'm allowed. Surely there's a way to get increased savings? Any help is appreciated, and I apologise in advance if I don't reply to everyone.