It's the fish swallows the hook to far just cut it best as you can and hopefully the fish will one day end up forcing it out on it's own.
A trout swallowed my hook before and i literally had cut as much as i could without killing it and leave it in the fish and hope one day it will come out on it's own. It might not have, but I did the best I could to get it out. And at least it's back in with the wild! You can't help if you can't reach it. As cruel as it may sound it's fishing.
Marc