Not many surgeons do that particular revision and even fewer do it well. It's much more complicated than you might think and thus the risks are higher also.
Why are you looking to revise? That certainly can and probably will determine your insurance coverage. Assuming you are insured, you can call the toll free number on the back of your card to get names of bariatric surgeons in your area. You'd then have to research which ones perform this procedure.
There are two that we see mentioned here often that are considered experts in this area. One is Dr. Ara Keshashian (sp?) in California. I can never remember the name of the other one for the life of me but hopefully someone will chime in here and give you more info.
If you're considering this option for any other reason than mechanical failure it would be hard to recommend proceeding. Fortunately for all of us you don't need my recommendation of course. Good luck, be careful and don't necessarily contract with the lowest bidder.
edited: you can also check in at the DS Forum and you'll probably get more feedback.
Note that Dr Keshishian (aka Dr K) is in Pasadena, CA, which is a suburb of Los Angeles. I highly recommend you contact his office for a phone consultation. I had complex abdominal surgery with him last summer and had a great experience; I also flew in from another state.