Functional results with regard to erectile function and urinary continence after prostate sparing cystectomy are good. Oncological results have been promising, but need to be confirmed after longer followup and in larger trials.
For men in need of a bladder removal for bladder cancer, my practice has always consisted of removing the entire prostate as well. This is what I learned at Indiana and have continued to do in NJ. As far as I know, urologic oncologists in the USA all agree on this.
In Europe I have read several studies that have left the prostate capsule or most of the prostate in place. I think you will see a higher rate of pelvic recurrences and bladder cancer recurrence in the prostate, as well as new prostate cancers this way. I do agree that men will have less side effects in regards to erections and continence potentially.
I have been performing robotic cystectomies for about 3 years now and feel that I can perform a more careful operation around the erection nerves and urinary muscles. I hope to improve on our past results while still removing the entire prostate with the bladder.