Dave, Google, cook s curve dilators, so you can see what is used.
In my case they used the camera to insert a guide wire through the very small hole into the bladder they then pull the camera out but leave the guide wire in. They then pass the smallest dilator over the guide wire and through the stricture, this stretches the stricture without cutting into it. The dilator is removed and the next size is passed over the guide wire. This process is repeated size by size until the biggest one has been used and the opening has been stretched. The camera is then passed over the guide wire and into the bladder to inspect the bladder.
Most of my procedures were done under GA but on one occasion I had it done in clinic without any anesthetic or pain relief. Not in my top ten of favourite activities but I would do it again if required.
I did wonder what happens if tamusolin relaxes the smooth and the bladder muscles. Do you self cath at regular intervals or when the brain / bladder says you need urinate. Does the urine come out of the catheter with force or just dribble out ,have you ever checked the flow rate from the catheter.
I can't remember if you have had a urodynamics test or not. That should establish whether the bladder is producing enough pressure to get past the obstruction. Or if the issue is with the sphincter or sphincters depending on what you have left.
Hopefully the drugs might have a beneficial effect.
Thanks Chris