Not sure what should take 6-8 hrs unless that includes the cystoscopy with laser, stone removal , etc but that seems hella long and drawn out.
The 6-8 hours is how long it takes her to recover from the anesthesia. The procedure should be 2-3 hours. He did say it might be a little longer if he thinks he has a good chance of getting it all in this one shot. But he is concerned with the anesthesia.