The important thing is to get started on the blood-flow enhancing rehab, if you believe any of the uros I have talked to. They have widely different ideas on when, how, and how much, but "if" has always been a given. The video James C. pointed out is by a well known and very reputable doctor.
I was put on 5mg per day Cialis a couple of months after surgery. I had to stop it during my IGRT (it caused minor low back pain, but that is not compatible with lying perfectly still for 12 minutes). I was "no nerves spared", so it may not ever accomplish anything, but I've spent more $ on things that didn't even have a hope of a return at the start. I'm still trying to be optimistic.
I added Trimix last fall, and, it works. I wish I had tried it earlier.