Great news about your kitty! If it makes you feel any better, my Dalmatian was blocked up with bladder stones when he was 12 and starting to get arthritic. We went ahead and did surgery (just like your cat, otherwise he would have died), and ended up with three more good years before he passed away, and no more bladder stones. I'm not sure how they do the incisions on a cat, but they cut right down the urethra on my dog and when he got home the urine just ran straight out of him. I thought perhaps they had damaged the sphincter, but after several days he was continent again and went back to normal. Just in case something like that happens with your cat, it may not be permanent.