What you are experiencing is common with a stricture problem. The depth of the stricture is what the problem is. I just had the proceedure and it was great for a few week. Mine was a shallow stricture so the scar tissue that formed after the proceedure was not too bad and I have a decent stream now. All he did with me is to make a few slices to open it up. The doc told me I was lucky. The more work they have to do in there the more scar tissue.
Hope they can find a better proceedure for you.