I'm not sure of the statistics, but I'm sure it is pretty low. I'm very sorry to hear of your loss. There are tests you can have done before the procedure to make sure that there isn't possible reactions to the type of anethetic they use. It doesn't cost that much for peace of mind.
Also, I hope you will reconsider getting a new kitty declawed. I don't know how much your vet told you about what the procedure actually involves. I know that my vet didn't tell me anything, just recommended it. The procedure actually involves the amputation of the first knuckle of kitty's paws, not just the removal of the nail bed (that's what my vet told me). It is very painful for kitty to recover from. My baby's paws got infected really bad and I almost lost him. There are also a lot of behavioural problems that can develop after this procedure is done. They may have litterbox problems because it hurts them to scrape in the litter so they will go where there isn't litter. They may become aggressive biters since their first line of defence, their claws, are taken away. They can also develop arthritis later in their lives. All this is if the surgery is performed successfully, nevermind when there are complications or it is botched. Kitties can be taught not to scratch furniture and people. Most of them are really good about it if they have alternatives to the couch like scratching posts. Check out the Declawing Sticky at the top of this forum for more information.
I hope I don't come off as preachy. I was uninformed when I had this done to my kitten. The vet didn't explain anything to me or tell me of the possible problems. All they wanted was more money. Had I been informed I never would have gotten this done.